Answer:
(8, 5) (Answer C)
Step-by-step explanation:
Write this system of linear equations in a (vertical) column:
4x - 3y = 17
5x + 4y = 60
Let's eliminate y through addition/subtraction:
Multiply 4x - 3y = 17 by 4, obtaining 16x - 12y = 68, and
multiply 5x + 4y = 60 by 3, obtaining 15x + 12y = 180. Then we have:
16x - 12y = 68
15x + 12y = 180
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31x = 248, and so x = 248/31 = 8.
Now find y. Substitute 8 for x in 5x + 4y = 60: 5(8) + 4y = 60, or
4y = 60 - 40 = 20.
Thus, y = 20/4, or y = 5.
The solution is (8, 5) (Answer C)
% increase = Increase ÷ Original Number × 100.<span>
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10 of the employees are certified mechanics.
Use this formula a2 − b2 = (a + b)(a − b)
<span>(x+1)^2-(x-1)^2 in this case, a = x+1, b = x-1</span>
<span>= [(x+1) + (x-1)] * [(x+1) – (x-1)]</span>
=(x +1 + x – 1) *(x +1 – x +1)
= 2x * 2
<span>=4x</span>
