# How do I solve the following equations: x/100 = -10/25  and 80x-160=3440? Thanks for your help

sciencesolve | Teacher | (Level 3) Educator Emeritus

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You need to solve the  equation  `x/100 = -10/25 ` hence you need to add both sides `10/25 ` such that:

`x/100 + 10/25 = 0`

You need to bring the fractions to a common denominator, hence you need to multiply the fraction `10/25`  by 4 such that:

`x/100 + 40/100 = 0 =gt (x+40)/100 = 0 =gt x+40 = 0 =gt x = -40`

You need to solve the  equation  `80x-160=3440` , hence you need to isolate to the left side the term containing x such that:

`80x = 3440 + 160 =gt 80x = 3600 =gt 8x = 360 =gt x = 360/8 =gt x = 45`

Hence, the solution to the equation  `x/100 = -10/25` is  `x = -40 ` and the solution to the equation `80x-160=3440 ` is `x = 45` .

atyourservice | Student, Grade 11 | (Level 3) Valedictorian

Posted on

x/100 = -10/25  and 80x-160=3440

`x/100 = -10/25`

all you need to so is cross multiply:

`x xx 25 = 25x`

`-10 xx 100=-1000`

set the result equal to each other

25x = -1000

divide by 25 to get x by itself

`(25x)/25 = -1000/25`

x= -40

as for the second problem:

80x-160=3440

just move the 160 to the other side of the equal side by adding

80x-160=3440

+160  +160

80x=3600

divide by 80 to get x alone

`(80x)/ 80 = 3600/80`

x = 45