Sarah weighs 30 more than 2 times as sheila. Together they weigh 150 kilograms. What is the wieght of each in grams

Sheila - 40kg

Sarah - 110kg

40 x 2 = 80

80 + 30 = 110

I used trial and error, starting with 50, to work this out. Here's what I did:

Sh x2 Sa Sh + Sa

50 100 130 180

45 90 120 165

40 80 110 150

Sh = Sheila

Sa = Sarah

Sh + Sa = Sheila + Sarah

Assume Sheila weighs x,

so Sarah weighs 2x+30

together x+2x+30=150

remove 30 to the other side

3x=120

x=40

so Sheila weighs 40

and Sarah 2*40+30=110