Two pictures hope this would help you
For the expression 28-28z to have a negative value, what must be true about the value of z?
1 answer:
You might be interested in
Answer:
y = x²/4 + x/2 + 21/4 ⇒ -9 ≤ x ≤ 7
Step-by-step explanation:
∵ x = 2t - 1
∴ 2t = x + 1 ⇒ t = (x + 1)/2
∵ y = t² + 5
∴ y = [(x + 1)/2]² + 5 = (x² + 2x + 1)/4 + 5
y = x²/4 + x/2 + 1/4 + 5 = x²/4 + x/2 + 21/4
∵ -4 ≤ t ≤ 4
∴ -9 ≤ x ≤ 7
