Answer:
D. 10^10
Step-by-step explanation:
Multiplying numbers with exponents rule : 
explanation of rule : we simply keep the bases the same and add the exponents.
10^3 • 10^7
keep the base as 10 and add the exponents

Keep in mind that this only works when the bases are the same.
Answer:
n+18=7(n-3)
Step-by-step explanation:
Lets replace "A number" with the variable n because we do not know its value!
1) Rewrite the problem as an equation
n+18=7(n-3)
<u>If we want to solve the equation, do the following:</u>
1) Distribute 7 to n and -3:
n+18=7n-21
2) Add 21 to both sides:
n+39=7n
3) Subtract n from both sides:
39=6n
4) Divide both sides by 6:
n=6.5
Answer:
A 161 square feet
Step-by-step explanation:
5×5=25
1/2 of 25 is 12.5(triangular face) ×2=25
5×8 is 40 (base and left face)
8×7 is 56 (right face)
25+40+40+56=161
There are 3 available methods - Substitution , Elimination and <span>Matrix.
</span>The substitution<span> method is used to eliminate one of the variables by replacement.
</span>
The elimination method<span> is used for solving linear systems.
</span>
<span>A Matrix is an array of numbers.
</span>
Lets use Substitution to solve this system.
Now substitute <span>
</span>
Hence -