The difference between the means is about 5 times
X = girls
Y = boys
X + y = 428
Answer:
A. 84x - 16y - 10.6
Explanation:
apply distributive method: a(b + c) = ab + ac
9514 1404 393
Answer:
a. (-1/2, 5)
Step-by-step explanation:
The coefficients of x have opposite signs, so the x-terms can be eliminated by adding the two equations.
(2y -12x) +(3y +12x) = (16) +(9)
5y = 25 . . . . . . simplify
y = 5 . . . . . . . . .divide by 5
This matches only answer choice A.
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<em>Check</em>
The other part of answer choice A is x = -1/2. We can test this to make sure it works:
2(5) -12(-1/2) = 16
10 + 6 = 16 . . . . . . true, the selected answer works OK
