Question

lesson practice 8.4.06 spiral review problems 9 - 10: solve each equation. show your thinking. 9. -4(r + 2) = 4(2 - 2r) 10. 1.3 + 6d = 2.

Explanation:

Step1: Expand both sides

$-4(r+2) = 4(2-2r)$
$-4r - 8 = 8 - 8r$

Step2: Isolate r terms

Add $8r$ to both sides:
$-4r + 8r - 8 = 8$
$4r - 8 = 8$

Step3: Isolate constant terms

Add 8 to both sides:
$4r = 8 + 8$
$4r = 16$

Step4: Solve for r

Divide by 4:
$r = \frac{16}{4}$

Step5: Isolate d terms (for #10)

$1.3 + 6d = 2.5$
Subtract 1.3:
$6d = 2.5 - 1.3$
$6d = 1.2$

Step6: Solve for d

Divide by 6:
$d = \frac{1.2}{6}$

Answer:

For problem 9: $r = 4$
For problem 10: $d = 0.2$