You need to use the distributive property. So you take the -9 from outside the parentheses and multiply itself by the numbers inside.
Answer:
x = 9±sqrt(7)
Step-by-step explanation:
3(x-9)^2 =21
Divide each side by 3
3/3(x-9)^2 =21/3
(x-9)^2 =7
Take the square root of each side
sqrt((x-9)^2) =±sqrt(7)
x-9 =±sqrt(7)
Add 9 to each side
x = 9±sqrt(7)
Answer:
B
Step-by-step explanation:
Because i did this problem
Hello :
the terme general is : an = a1 +(n-1)d
a11 = a1+(11-1)×5
a11 = -12+50
a11 = 38
<span>the sum of the first 11 terms is : S11 = (11/2)(a1+a11)
</span>S11 = (11/2)(-12+38)
S11 = 143
