I am working on some practice quiz for math... Can someone double check my work???

Question

1. Find the perfect square trinomial whose first two terms are q^2 + 3q= My answer is q^2 +3q+9.
2. Factor the perfect square trinomial. u^2-15u+50=
My answer is (u-5)(u+10)
3. Solve by completing the square. 3x^2+5x-1=0
My answer is {5-sqrt37/6, 5+sqrt37/6}
4. Solve: sqrt-x+7 = x-1
My answer is 0
5. Solve by factoring: q^2+4q+4=0
My answer is: {-2,2}

Answer 1

#2 is incorrect. It should be (u-5)(u-10)

#3 I got (sqrt 37)/6 -5/6 which can be combined to [(sqrt 37)-5]/6

#5 is incorrect. The solution is -2 only.


For #4 it's difficult to tell from your equation whether you mean sqrt (x+7) or sqrt(x) +7

Answer 2

Sorry, all your answers are wrong!
Let's do these one at a time
1). To find the constant to make q²+3q a square
take HALF the middle coefficient, square it
and add it to q²+3q. Half of 3 is 1.5 and its
square is 2.25, so your answer should be
q²+3q+2.25 = (q-1.5)².

2). The factors should be (u-5)(u-10). You
have the wrong sign on the 10.

3). Your answers are almost right. The 5's should
be -5's.

4). √-x + 7 = x-1
This yields
√-x = x-8
Now square both sides:
-x = x²-16x+64.
or
x²-15x+64=0.
Since b²-4ac < 0, this equation has no real roots.

5. q²+4q+4=0
This gives
(q+2)(q+2)= 0
So the roots are -2 and -2.
We say the equation has a double root at -2.
If you draw the graph of the equation, it
will be tangent to the x-axis at x = -2.

Answer 3

congratulation! All your answers are wrong. I really don't understand what you are up to when you say you are working on some practice quiz for math. Is that another way of saying you are bogged down? Anyway, here are the correct answers;

1. q ^2 +3q+ (9/4)

2. (u-5)(u-10)

3. {(-5-sqrt37)/6, (-5+sqrt37)/6}

4. either x = -2 or x = 3

5. {2,2}

Answer 4

2. Factor: u^2 - 15u + 50 > your solution is incorrect.

First: multiply the 1st & 3rd coefficient to get "50." Find two numbers that give you "50" when multilpied & "-15" (2nd/middle coefficient) when added/subtracted. The numbers are (-5 & -10).

Sec: rewrite the expression with the new middle coefficients...

u^2 - 5u - 10u + 50

*When you have 4 terms --- group "like" terms...

(u^2 - 5u) - (10u + 50)
u(u - 5) - 10(u - 5)
(u - 5)(u - 10)

5. Solve "q" by factoring: q^2+4q+4=0

Your answer is {-2, 2} but, the only solution that will work is 2, not -2.