Let m=2x+3m=2x+3m, equals, 2, x, plus, 3.

Which equation is equivalent to (2x+3)^2-14x-21=-6(2x+3)

2

−14x−21=−6left parenthesis, 2, x, plus, 3, right parenthesis, squared, minus, 14, x, minus, 21, equals, minus, 6 in terms of mmm ?

or  

Step-by-step explanation:

you have a definition for the variable m:

and then you are asked to find the equivalent equation to:

in terms of m, what we need to do is substitute all the we find in the expression, for an m (because of the definition ), this way we get the following:

we still have to write in terms of m for that we factor a -7, and we get:

we have found an equivalent to  which contains and since we know that :

and we substitute this into the equation

this equation is now what we anted, the original expression  in terms of m. you can represent the result like this:

or what is the same:

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13