+912 1. What is the solution to the system of linear equations?
−8x − 7y = 96
−3x + 5y = −25
2. Marty is 3 years younger than 6 times his friend Warren's age. The sum of their ages is greater than 11.
What is the youngest age Warren can be?
Enter your answer, as a whole number, in the box.
3. What is the interval notation for the compound inequality?
x ≤ 3 or x > 7
A.(−∞, 3) or [7, ∞)
B. (3,7]
C. [3,7)
D. (−∞, 3] or (7, ∞)
+9466 1.
-8x - 7y = 96 multiply this equation through by 5 to get -40x - 35y = 480
-3x + 5y = -25 multiply this equation through by 7 to get -21x + 35y = -175
(-40x - 35y) + (-21x + 35y) = 480 + -175
-61x = 305
x = -5 Use this value for x in the second given equation to find y .
-3(-5) + 5y = -25
15 + 5y = -25
5y = -40
y = -8
2. Let Marty's age be " m " , and let Warren's age be " w " . The problem tells us that...
m = 6w - 3
and
m + w > 11
Plug in 6w - 3 for m into the inequality.
6w - 3 + w > 11 Add 3 to both sides and combine like terms.
7w > 14
w > 2 Warren has to be older than 2 .
So if his age has to be a whole number, the youngest he can be is 3 .
3. (−∞, 3] or (7, ∞)
+9466 1.
-8x - 7y = 96 multiply this equation through by 5 to get -40x - 35y = 480
-3x + 5y = -25 multiply this equation through by 7 to get -21x + 35y = -175
(-40x - 35y) + (-21x + 35y) = 480 + -175
-61x = 305
x = -5 Use this value for x in the second given equation to find y .
-3(-5) + 5y = -25
15 + 5y = -25
5y = -40
y = -8
2. Let Marty's age be " m " , and let Warren's age be " w " . The problem tells us that...
m = 6w - 3
and
m + w > 11
Plug in 6w - 3 for m into the inequality.
6w - 3 + w > 11 Add 3 to both sides and combine like terms.
7w > 14
w > 2 Warren has to be older than 2 .
So if his age has to be a whole number, the youngest he can be is 3 .
3. (−∞, 3] or (7, ∞)
