Find -30 + (-15) + 70.
select one:
a. 55
b. 25
c. -55
d.-25

B

Step-by-step explanation:

Note that + ( - ) is equivalent to -

Given

- 30 + ( - 15) + 70

= - 30 - 15 + 70

= - 45 + 70

= 25 → B

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions

-2

7 - 9 = -2

reversed:

-2 + 9 = 7