Question

4 x plus 8 y equals 40, when y equals 0.8?

Answer 1

Answer:

$\boxed{ \bold{ \huge{ \boxed{ \sf{x = 8.4}}}}}$

Step-by-step explanation:

Given, y = 0.8

To find : value of x

$\sf{4x + 8y = 40}$

plug the value of y

$\longrightarrow{ \sf{4x + 8 \times 0.8 = 40}}$

Multiply the numbers: 8 and 0.8

$\longrightarrow{ \sf{4x + 6.4 = 40}}$

Move 6.4 to right hand side and change it's sign

$\longrightarrow{ \sf{4x = 40 - 6.4}}$

Subtract 6.4 from 40

$\longrightarrow{ \sf{4x = 33.6}}$

Divide both sides by 4

$\longrightarrow{ \sf{ \frac{4x}{4} = \frac{33.6}{4} }}$

Calculate

$\longrightarrow{ \sf{x = 8.4}}$

Hope I helped!

Best regards ! :D