Question

Copy and complete the table of values for y = 2x²+x+5.
What numbers replace A and B?

Answer 1

The answers are:

A = 11

B = 8

Work/explanation:

Plug in -2 for x.

`\sf{y=2x^2+x+5}`

`\sf{y=2(-2)^2+(-2)+5}`

Simplify

`\sf{y=2(4)-2+5}`

`\sf{y=8-2+5}`

`\sf{y=6+5}`

`\sf{y=11}`

Hence, A = 11.

Now let's find B.

Plug in 1 for x.

`\sf{y=2(1)^2+1+5}`

`\sf{y=2(1)+6}`

`\sf{y=2+6}`

`\sf{y=8}`

Hence, B = 8.

The result is:

`\begin{tabular}c\sf{x&y}\\\cline{1-2}\sf{-2 & 11}\\\sf{-1&6}\\\sf{0&5}\\\sf{1&8}\\\sf{2&15}\end{tabular}}`

Answer 2

A = 11 , B = 8

Explanation:

to find the values of A and B substitute the corresponding values of x above them in the table into y = x² + x + 5

x = - 2

y = 2(- 2)² + (- 2) + 5

= 2(4) - 2 + 5

= 8 + 3

= 11 ← value of A

x = 1

y = 2(1)² + 1 + 5

= 2(1) + 6

= 2 + 6

= 8 ← value of B

then table is

x | - 2 | - 1 | 0 | 1 | 2

----------------------------

y | 11 | 6 | 5 | 8 | 15