Question

_

Answer 1

can you turn those sentences into two equations?

Answer 2

and then just sub one of those equation into the other

Answer 3

hmm, not like that , the idea is to get an equation
with only one variable left in it .
__

if you sub
n = 8+2a into n-25=a
you'll get [8+2a] - 25 = a an equation for a
__

or if you sub
a=n-25 into n = 8+2a
you'll get n = 8+2[n-25] an equation for n

Answer 4

then its probably quickest so solve the equation for n

n = 8+2[n-25]
=
=

Answer 5

careful with those equations

n = 8 + 2[n - 25]
n = 8 + 2n - 50
=

Answer 6

yeah, go on

Answer 7

i dont understand that step, ?

Answer 8

n = 2n - 42

is right

now get all the n-tems to one sides of the equation

Answer 9

n = 2n - 42
misusing 2n from both sides
n -2n = 2n -2n - 42
simplify

Answer 10

*minus-ing

Answer 11

yeah that is good, now simplify the left hand side of the equation

Answer 12

yeah !

-n = -42

Answer 13

so n is . . .

Answer 14

cool, so what about a?

Answer 15

to find a now that you have n = 42
you could uses either of the equation you got at the start

n = 8+2a n-25 = a

the second one will be simpler

Answer 16

its simpler than than now you have found n

subbing in n=42
into n-25 = a

42 -25 = a
= a

Answer 17

the method you were tying would give the same answer
{8 + 2a} = a+25
8 +2a = a+25
a = 17

Answer 18

Yep , you've got it !

Answer 19

Thanks for showing your working , it makes it easier to see how to help \[\ddot\smile\]