Question

a) Calculati valoarea numarului real m penteu care 2 este solutie a ecuatiei :)
7mx - 3 (2m+5)x -11=4m-17

b) determinati a €R stiind ca 4 este solutie a ecuatiei :
4x-a (x+5)=2ax + 16

Answer 1

$a)x = 2$

$7mx - 3(2m + 5)x - 11 = 4m - 17$

$7m \times 2 - 3(2m + 5) \times 2 - 11 = 4m - 17$

$14m + ( - 6m - 15) \times 2 - 11 = 4m - 17$

$14m - 12m - 30 - 11 = 4m - 17$

$14m - 12m - 4m = - 17 + 30 + 11$

$- 2m = 24 \: | \div ( - 2)$

$m = - 12 \: \in \: \mathbb{R}$

$b)x = 4$

$4x - a(x + 5) = 2ax + 16$

$4 \times 4 - a(4 + 5) = 2a \times 4 + 16$

$16 - 4a - 5a = 8a + 16$

$- 4a - 5a - 8a = 16 - 16$

$- 17a = 0 \: | \div ( - 17)$

$a = 0 \: \in \: \mathbb{R}$