Maths-
General
Easy
Question
2ax − 15 = 3(x + 5) + 5(x − 1)
In the equation above, a is a constant. If no value of x satisfies the equation, what is the value of a ?
- 1
- 2
- 4
- 8
The correct answer is: 4
○ The concept used in the question is concept of the equation.
○ Given equations are linear equations in two variables.
○ In the elimination method, any of the coefficients is first equated and eliminated. After elimination, the equations are solved to obtain the other equation.
- Step by step explanation:
○ Given:
2ax − 15 = 3(x + 5) + 5(x − 1)
○ Step 1:
○ Simplify:
2ax − 15 = 3(x + 5) + 5(x - 1)
2ax − 15 = (3x + 15) + (5x - 5)
2ax − 15 = (3x + 5x) + (15 - 5)
2ax − 15 = 8x + 10
2ax − 15 = 8x + 10
2ax − 8x = 10 + 15
x(2a -8) = 25
x = 
○ Step 1:
○ For x to not satisfy above equation.
x should be not defined
∴ should be not defined
2a - 8 = 0
2a = 8
a = 4
∴ a = 4
- Final Answer:
Correct option is,
Option C. 4.
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