Write as a product of two polynomials a) 3a(2x–7)+5b(7–2x) b) (x–y)^2–a(y–x)
1 answer:
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9514 1404 393
Answer:
WX = 33
(x, y) = (2, 10)
Step-by-step explanation:
The hash marks tell you WX is a midline, so has the measure of the average of the two bases.
WX = (PQ +SR)/2 = (27 +39)/2 = 66/2
WX = 33
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The hash marks also tell you ...
PW = WS
y +4x = 18 . . . . . . substitute the given expressions
and also
QX = XR
2y +x = 22 . . . . . substitute the given expressions
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If you solve the first equation for y, you get ...
y = 18 -4x
Substituting that into the second equation gives ...
2(18-4x) +x = 22
36 -7x = 22 . . . . . . . simplify
14 = 7x . . . . . . . . . . . add 7x-22 to both sides
2 = x . . . . . . . . . . . . divide by 7
y = 18 -4(2) = 10 . . . find y using the above relation
The values of x and y are 2 and 10, respectively.
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My favorite "quick and dirty" way to solve a set of linear equations is using a graphing calculator. It works well for integer solutions.
Multiply the equation:
The solution set is the same, because multiplying both sides of an equation by a non-zero number doesn't change the solution set. In fact, if you rewrite the equation as
Multiplying this by 3 (or whatever number, for all it matters) gives
Now, a product is zero if and only if at least one of the factor is zero. So, either or
Since the first is clearly impossible, the second one must be true, which is the original equation.