4r - 8 = 5r + 12
4r - 5r = 12 + 8
-r = 20
r = -20 <===
One way of breaking apart the arrays is by partitioning the value 135
135 = 100 + 30 + 5
Then divide each value by 5
135 ÷ 5 = (100 ÷ 5) + (30 ÷ 5) + (5 ÷ 5)
135 ÷ 5 = 20 + 6 + 1
135 ÷ 5 = 27
Another method you can use is shown in the diagram below:
Answer:
8 x 9 maybe?
Step-by-step explanation: