9x-7= 29
9x-7+7= 29+7
9x= 36
Divide by 9 for 9x and 36
9x/9= 36/9
x= 4
Check answer by using substitution method
9x-7= 29
9(4)-7=29
36-7= 29
29= 29
Answer is x=4 (second choice)
Answer:
47
Step-by-step explanation:
10z + 4 + 8z + 2 = 168
first we find z
z = 9
5×9 +2 is 47
ANSWER IS 47
Plug in 3 for x
f(3)= 2(3)+8
f(3)=6+8
f(3)=14
g(3)=5
Then add the values
14+5=19
Final answer: 19
is the formula for calculating x1 and x2
To prove x1 + x2 = -b/a all we need to do is to express x1 and x2 from equation above
once we do we will get -2b/2a which is equal to -b/a because square root part will negate each other. one has + sign in front and other - sign
Showing that x1x2 = c/a goes similar way.
the numerator parts is actually difference of squares. after that we will have:
-b^2 -b^2 + 4ac = 4ac
in denominator we have 2a*2a = 4a^2
4ac/4aa = c/a