Step-by-step explanation:
Step 1: Multiply the 7 into the bracket.(make sure that your signs are correct)
Step 2: Minus the 21 from the 73.( Because when you take a value over the equal sign the value's sign changes)
Step 3: Minus 15y from 28y.
Step 4: Divide 52 by 13( because when you take the 13 over it divides ,because on the other side lf the equal the 13 multiples with the y)
