Answer:
u = - ( 9-6w)/2
Step-by-step explanation:
to evaluate for u in the expression -2u+6w=9 is simply to look for a way such that we would express u in terms of w and other variables.
solution
-2u+6w=9
-2u = 9 - 6w
divide both sides by the coefficient of u which is -2
-2u/u = 9 - 6w/-2
u = - ( 9-6w)/2
therefore the value of u when rearranged in the equation -2u+6w=9 is evaluated to be equals to
u = - ( 9-6w)/2
46: 24a+40
First we are going to take a look at a) 8(3a+5)
a) We then simplify it by multiplying the numbers inside the parenthesis by 8.
a) 24a+40
Now we ask ourselves, is this equivalent to 24a+40? YES!
So your answer for #46 is a) 8(3a+5)
Remark
It's a right triangle so the Pythagorean Theorem applies. All you have to do is put the right things in the right places of the formula.
Givens
a = x
b = x + 4
c = 20
Formula and Substitution.
a^2 + b^2 = c^2
x^2 + (x + 4)^2 = 20^2
Solution
x^2 + x^2 + 8x + 16 = 20 Collect the like terms on the left.
2x^2 + 8x + 16 = 20 Subtract 20 from both sides.
2x^2 + 8x + 16 - 20 = 0
2x^2 + 8x - 4 = 0 Divide through by 2
x^2 + 4x - 2 = 0
Use the quadratic formula
a = 1
b = 4
c = - 2

From which x = (-4 +/- sqrt(24) ) / 2
x1 = (- 4 +/- sqrt(4*6) ) / 2
x1 = (- 4 +/- 2 sqrt(6) ) / 2
x1 = -2 + sqrt(6)
x2 = -2 - sqrt(6) This is an extraneous root. No line can be minus.
x1 = + 0.4495
x2 = x + 4 = 4.4495
the answer would be 4 9/14
4 9/14