Question

Can someone explain some SAT math questions?
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1. If x^2 + y^2 = 30 and xy = 8. What is the value of (x-y)^2

The answer is 14
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2. If 2^(3n+2) = 4^(n+4), what is the value of n.

The answer is 6.
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3. If k and h are constants and x^2 - kx + 18 = (x-3)(x-h), what is the value of k.

The answer is 9.
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Answer 1

sat is hard

Answer 2

I will only give you an example of SAT.

Answer 3

What is the area, in square feet, of the triangle whose sides have lengths equal to 10, 6 and 8 feet?

Solution

If given the three sides of a triangle and asked to find the area of the triangle, we normally use Heron's formula. However the triangle given here is a special triangle. Note that the three sides of the given triangle are related as follows

√(62 + 82) = 10

which means that the triangle is a right triangle and its hypotenuse is 10 and legs 6 and 8. The area A is given by

A = (1/2)(6)(8) = 24 feet2

Answer 4

Sorry, but that doesn't help me solve algebra problems. >.<
I took the test which had those questions, but don't understand them.

Answer 5

algebra? are you in a grade schooler student?

Answer 6

No, it's just SAT prep.

Answer 7

x+2y=1......(1)

2x+y=8......(2)

We will use the elimination method.

First, multiply (1) by -2 and add to (2)

-2x-4y=-2

2x+y=8

==> -3y=6 ==> y=-2

x+2y=1

==> x= 1-2y = 1-2(-2)= 1+4= 5

like this ? what do you think?

Answer 8

hints :
1) \(\Large (x-y)^2 = x^2 +y^2 -2xy\)

2) write 4 = 2^2, then compare the exponents

3) FOIL, right side, then compare the co-efficients