Question

Help me !!! please 50 points!!

A system of equations is shown below: 1. Equation A: 4c = d − 8 Equation B: c = 5d + 8 Which of the following steps should be performed to eliminate variable d first? (5 points)


Multiply equation B by 4. Multiply equation A by −5. Multiply equation A by 4. Multiply equation B by 5. 2 . A system of equations is shown below: n = 3m + 7 n − 2m = 1 What is the solution, in the form (m, n), to the system of equations? (5 points)


(3, 7) (1, 8) (−3, −2) (−6, −11) 3. A system of two equations is shown below: Equation C: a = 3b + 6 Equation D: a = 7b − 1 What value of a can be substituted into equation D to solve the system of equations? (5 points)

Answer 1

the first step to eliminate d is to multiply equation B by 5

second :(m,n) (-6,-11)

value of a can be substituted into equation D to solve the system of equations is 7b-1

Explanation:

first equation:

4c=d-8 or 4c-d=-8

c=5d+8 or c-5d=8

so the first step to eliminate d is to multiply equation B by 5

second equation :

n=3m+7 or n-3m=7

n-2m=1

n-3m=7

solve :

1-eliminate n by subtracting two equation : : n-2m-(n-3m)=1-7

-2m+3m=-6

m=-6

substitute m: n-3(-6)=7 , then n+18=7

n=7-18=-11

third :

a=3b+6 or a-3b=6

a=7b-1

find a

a-3b=6

value of a can be substituted into equation D to solve the system of equations is 7b-1