Question

What is the value of y in the formula shown when x = 45?

y = 4x + √x + 0.2  - 5x

y =

Answer 1

`\displaystyle\\x = 45\\\\y = 4x + √(x) + 0.2  - 5x\\\\y = 4\cdot45 + √(45) + 0.2  - 5\cdot45\\\\y = 180 + √(9\cdot5) + 0.2  - 225\\\\y = 180 + 3√(5) + 0.2  - 225\\\\y = 180 - 225 + 0.2 + 3√(5)\\\\y = -45 + 0.2 + 3√(5)\\\\\boxed{\bf y = -44.8 + 3√(5)}`