Answer:
First option
Step-by-step explanation:
The result of first expression:
7(6+z) multiply 7 with inside the parenthesis
7(6+z) = 42 + 7z
the result of second expression:
since we need to do multiplying first,
7*6 = 42 and 7*z = 7z
then we add them
42 + 7z this is the same result we found for the first equation
Attached solution with detailed work.
10+2(x)=5(x-7)
10+2(x)=5(x)-35
35+10=5(x)-2(x)
45=3(x)
45/3=x
x=15
31,
because when you divide 42 and 12 to get the other two sides you get 3.5 and
3.5+3.5+12+12=31