Question

Evaluate -1/2 x² + 3/4 x for x = 4.

Answer 1

ANSWER:

• -5

Solution:

1.Substitute

• Substitute x = 4 into $\sf{ - \frac{1}{2} {x}^{2} + \frac{3}{4} \times }$
• $\sf{ - \frac{ {4}^{2} }{2} + 4 \times \frac{3}{4} }$

2.Calculate

• $\sf{ - \frac{16}{2} + 4 \times \frac{3}{4} }$
• Cross out the common factor
• $\sf{ - 8 + 4 \times \frac{3}{4} }$
• Cross out common factor
• $\sf{ - 8 + 3}$
• Calculate the sum or difference
• -5

Hope it helps