Question

y=ax-4, find a if:
y= 1/2
x= - 2/5
​

Answer 1

$y = ax - 4 \\ = > \frac{1}{2} = a \times \frac{ - 2}{5} - 4 \\ = \frac{1}{2} + 4 = \frac{ - 2a}{5} \\ = > \frac{ - 2a}{5} = \frac{1 + 8}{2} \\ = > \frac{ - 2a}{5}= \frac{9}{2} \\ = > - 2a = \frac{9 \times 5}{2} \\ = > a = \frac{45}{2 \times ( - 2)} \\ = > a = \frac{ - 45}{4} \\ = > a = - 11.25$

Hope it helps you... thanks

Answer 2

Given: y = ax - 4, y = 1/2 and x = -2/5.

To find: The value of a.

Answer:

$\sf y = ax - 4\\\\Substituting\ the\ values\ of \ x\ and\ y\ in\ the\ above\ equation,\\\\\frac{1}{2}= (a\times \frac{-2}{5}) - 4\\\\\frac{1}{2} = \frac{-2a}{5}- 4\\\\\frac{1}{2} = \frac{-2a}{5} - \frac{20}{5}\\ \\\frac{-2a}{5} - \frac{20}{5} = \frac{1}{2}\\\\-2a - 20 = \frac{5}{2} \\\\-2a = \frac{5}{2} + 20\\\\-2a = \frac{5}{2} + \frac{40}{2} \\\\-2a = \frac{45}{2} \\\\a = \frac{45}{2} \times \frac{-1}{2} \\\\a = \frac{-45}{4}$

Therefore, a = -45/4.