Question

Subtract 40a+20b-90c from 20a-40b​

Answer 1

Answer:

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Step-by-step explanation:

Given: #1 A + B = 50, #2 B + C = 30 & #3 C + A = 40

A+B=50 (#1 given)

-B-C=-30 (#2 multiplied both sides by -1) #4

A-C= 20 (add #1 & #4) #5

A+C=40 (#3 given)

2A=60 (Add #3 & #5)

A = 30 (divide both sides by 2)

30 + B = 50 (replace A with the answer 30 to #1)

B = 50 - 30 = 20 (subtract 20 from both sides)

30 + C = 40 (replace A with the answer 30 to #3)

C = 40 - 30 = 10 (subtract 30 from both sides)

30–20–10=0 (replace all variables with answers)

the result is equal to zero QED

Answer 2

40a+20b-90c

20a-40b

____________

20a-20b-90c

____________

this is answer I hope it helps you.