The answer of part a is y = 8
The answer of part b is RS = 69, ST = 28
Explanation:
a. Since RT = RS + RT, subsitute values of RS and RT in the equation
97 = (8y + 5) + (3y + 4)
97 = 11y + 9
97 - 9 = 11y
88 = 11y
y = 8
b. Subsitute the value of y in RS and ST just like done in part a