Question

The value of a² if the expression (5x²+6x−7a) equals to 4 for x=2 is​

Answer 1

Answer:

16

Step-by-step explanation:

5x² + 6x - 7a = 4

Given x = 2

5×(2)² + 6×(2) - 7a = 4

5×4 + 12 - 7a = 4

20 + 12 - 7a = 4

32 - 7a = 4

32 - 4 = 7a

28 = 7a

4 = a

★ The value of a² is -

a = 4

= a²

= 4²

= 16

Hope it will help you..!!

Answer 2

$5 {x}^{2} + 6x - 7a = 4$

$5 {(2)}^{2} + 6(2) - 7a = 4$

$5(4) + 12 - 7a = 4$

$20 + 12 - 7a = 4$

$32 - 7a = 4$

$- 7a = 4 - 32$

$- 7a = - 28$

$a = \frac{ - 28}{ - 7}$

$a = 4$

${a}^{2} = ( {4)}^{2}$

$= 16$