Answer:
Step-by-step explanation:
We are given with two equations
first equation is 
second equation is
we find the result of subtracting two equation
subtract the second equation from the first, so
first equation - second equation, multiply second equation by -1 and then add it with first equation
Now add both equations, we get
(6 + 3) + 21 = 6 + (3 + 21)
It's an ASSOCIATIVE PROPERTY
(a + b) + c = a + (b + c)
Answer:
x=-8.5.
Step-by-step explanation:
First, write an equation. Twice x (2x) plus 7 (+7) is the same as (=) negative ten (-10), or 2x+7=-10. To solve, first subtract 7 from both sides to get 2x=-17. Then, divide both sides by 2 (x=-8.5).
2/7.
2/7 + 5/7 =1 Just add the numerator if the denominator is the same
