Answer:

Step-by-step explanation:
Isolate x on one side of the equation.
2(-2x-4) ← (Expand by using with distributive property.)
<u><em>DISTRIBUTIVE PROPERTY</em></u>
⇒ A(B+C)=AB+AC
⇒ A(B-C)=AB-AC
A=2
B=(-2x)
C=4
2(-2x)-2*4
-2*2x-2*4
-2*2x-2*4 (Solve.)
-2*2-2*4=-4x-8
Rewrite the equation problem.
10-x=-4x-8
10-x-10=-4x-8-10 (Subtract 10 from both sides.)
Solve.
-x=-4x-18
-x+4x=-4x-18+4x (Then, add 4x from both sides.)
3x=-18 (Solve.)
3x/3=-18/3 (Divide by 3 from both sides.)
-18/3 (Solve & Simplify.)
-18/3=-6
X=-6

Therefore, the correct answer is x=-6.
Answer:
13
Step-by-step explanation:
you use the system of equations...
:)
Could I see the shape? I don’t think you uploaded the image to see the shape above.
Basically if you have an exponent at the end of a 10,

, then in the end the extended notation is going to have 7 zeros. So it'll be 10000000. Then you multiply whats in the rest of the equation together. There's the beginning :) I hope it helps.
The formula to find any term of an an arithmetic sequence is given by

=

=(n-1)d,
where we have first term

=8,
and d which is the common difference , and n is the term we need to find (in our case is 20)
the difference d=3, as you see each number is the previous minus 3
for S20=8+(20-1)*(-3)=8+(19)*(-3)=8-57=-49
S20=-49, this the 20th term