How many solutions are there to 3x-10(x+2) =13-7x

This is the following way to solve this problem:

3x-10(x+2)=13-7x

3x-10x-20=13-7x        (multiply 10 times what's in the parentheses)

-7x-20=13-7x              ( subtract 3x from -10x)

-7x-20-13=-7x             ( since the 13 is positive, when we move it to the other

                                   side, we change it's sign, so now we subtract 13 from 20

-7x-7=-7x

-7=-7x+7x                   ( we do the same thing we did above, now with the -7x)

-7=x

x=-7

x = -7

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step-by-step explanation:

abc

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for