Mathematics · Quantitative Aptitude
Algebraic Equations and Expressions
142 Questions
Algebraic equations and expressions test mathematical skills in solving for unknown variables. Questions involve linear equations, ratios, and evaluating complex expressions. This topic forms a core component of quantitative aptitude sections in various competitive exams.
Linear equationsEvaluating expressionsRatio proportionsExponential equationsHypergeometric functions
Algebraic Equations and Expressions Questions
A
Correct answer
Explanation
2x - 12 = -4x - 24
Bring subject terms to one side and non subject terms to another side
2x + 4x = -24 + 12
6x = -12
Dividing both sides by 6
x = -2
A
Correct answer
Explanation
–48x + 36 = -18x – 174
Bring subject terms on one side and non subject terms on another side
48x – 18x = 174 + 36
30x = 210
Dividing both sides by 30
x = 7
C
Correct answer
Explanation
8x + 10 = 10x
Subtract 8x from both side
10x - 8x = 10
2x = 10
Dividing both sides by 2, we get
x = 5
-
X + 5
-
2X2 + 3
-
2X2 + 5X
-
3X2 + 2
-
X2 + X + 2
B
Correct answer
Explanation
Assume X as 3. Then (1) = 8, (2) = 21, (3) = 33, (4) = 29 and (5) = 14. So (1) and (5) is not the answer. Let take X = 2 then (2) = 11, (3) = 18, and (4) = 14. Only choice (2) is odd in both cases.
B
Correct answer
Explanation
Left side: (12x)_3 = 1 * 3^2 + 2 * 3^1 + x * 3^0 = 9 + 6 + x = 15 + x. Right side: (123)_x = 1 * x^2 + 2 * x^1 + 3 * x^0 = x^2 + 2x + 3. Solving: 15 + x = x^2 + 2x + 3, so x^2 + x - 12 = 0, giving x = 3 or x = -4. Since base must be > 3 (digit 3 present), x = 3.
C
Correct answer
Explanation
2x + 3 = 4
Or 2x = 1
Or 4x = 2
Therefore, 4x + 2 = 4
B
Correct answer
Explanation
The given equation is 3(2x + 1) = 7.
According to the distributive property of multiplication, 3 × 2x + 3 × 1 = 76x + 3 = 7
Transposing 3 to R.H.S, we get:
6x = 7 – 36x = 4
Dividing both sides of the equation by 6, we get:
x = 4/6 = 2/3
The required value of x is 2/3.
Thus, the required value of (4x – 3) is -1/3.
This answer is correct.
B
Correct answer
Explanation
The given equation is 2(3x - 4) = 6
According to the distributive property of multiplication,
3 x -4 = 3
3x = 3 + 4
x = 7/3
Now, (5x + 2) = 5(7/3) + 2 = 35/3 + 2 = 41/3
This answer is correct.
-
X = 1/2
-
X = - 1/2
-
X = - 3/2
-
X = 3/2
-
None of these
C
Correct answer
Explanation
Yes, - 3/2 + 1/2 = - 1 is the correct answer.
A
Correct answer
Explanation
9/x = 3
9/3 = x
3 = x
x = 3
B
Correct answer
Explanation
8x - 8 = 56
8x = 56 + 8
8x = 64
x = 64/8
x = 8
A
Correct answer
Explanation
(x + 1/x) = 3
(x + 1/x)2 = 9
Or x2 + 1/x2 + 2 = 9
x2 + 1/x2 = 7
-
if (x == 0) return 0;
-
return 1;
-
if (x >= 2) return 2;
-
if (x == 0) return 1;
-
if (x <= 1) return 1;
E
Correct answer
Explanation
A factorial function needs a base case to terminate recursion. For factorial, 0! = 1 and 1! = 1. Option E handles this correctly: when x <= 1, return 1. Otherwise, it recursively computes x * factorial(x-1). Options A and D are incomplete (they don't handle x=1). Option B would cause infinite recursion for x > 1. Option C would return incorrect values.
B
Correct answer
Explanation
Operator precedence: * has higher precedence than +. So 2*3=6 and 4*5=20, then 6+20=26. The expression is evaluated as (2*3) + (4*5), not 2*(3+4)*5 or left-to-right.
A
Correct answer
Explanation
The expression is (c != 'p' || i + f <= 10). Since c is 'W', c != 'p' is true. In an OR expression, if the first part is true, the whole expression is true (1).