Which equation is equivalent to 3[x  +  3(4x  –  5)]  =  15x  –  24?

Hello from MrBillDoesMath!

x = 7/8

Discussion:

3[x + 3(4x – 5)] = 15x – 24 =>

3x + (3*3)(4x-5) = 15x - 24  =>

3x + 9*(4x) - (3*3)*5 = 15x - 24 =>

3x + 36x  - 45 = 15x - 24  =>   (add 24 to each side)

3x + 36x - 45 + 45 = 15x - 24 + 45 =>

39x = 15x + 21  =>                    (as 45-24 = 21)

39x-15x = 21 =>                        (subtract 15x from both sides)

24x = 21 =>

x = 21/24 = -7/8

Regards,  

MrB

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d. 145*2 is 290 than the total angle is 360 then minus 290 then divide by two