Question

Help me please and thank you

Answer 1

Since the shape is a parallelogram, there are 2 pairs of opposite but equal sides --> "6a+21" and "20a+7" "11a" and "4a+7"

The easier pair is

11a = 4a+7 Subject 4a from both sides

7a = 7 Divide 7 from both sides

a = 1

A = 1