Question

unit 2 - simplifying expressions
use substitution to find y.
y = 3 + 8.5x, when x = -4
y = x - 15, when x = 2.65

Explanation:

Step1: Substitute $x=-4$ into first equation

$y = 3 + 8.5\times(-4)$

Step2: Calculate the product first

$y = 3 + (-34)$

Step3: Compute final value for first $y$

$y = 3 - 34 = -31$

Step4: Substitute $x=2.65$ into second equation

$y = 2.65 - 15$

Step5: Compute final value for second $y$

$y = -12.35$

Answer:

1. $y = -31$
2. $y = -12.35$