Answer:
1. 21 and 29
2. 93 (or more specifically ≥ 93)
Step-by-step explanation:
1. Sum of two numbers is 50, x + y = 50
Second number is 8 more than the first number, y = x + 8
By substitution,
x + y = 50
x + x + 8 = 50
2x + 8 = 50
2x = 50 - 8
2x = 42
x = 21
21 + y = 50
y = 50 - 21
y = 29
2. Scores are 93, 89, 85, and x.
What must be the value of x so that:
(93 + 89 + 85 + x) / 4 ≥ 90
(no less than 90 means it must be greater than or equal to 90)
Solve for the equation
(93 + 89 + 85 + x) / 4 ≥ 90
(267 + x) / 4 ≥ 90
66.75 + (x/4) ≥ 90
(x/4) ≥ 90 - 66.75
(x/4)*4 ≥ 23.25*4
x ≥ 93
Therefore, the last score must be equal to or greater than 93.
