30 points! what is the first step to solve the following system of equations using substitution?

The answer to your question would be C.

Step-by-step explanation:

Substitution method can be applied in four steps

Step 1:

Solve one of the equations for either x = or y = .

Step 2:

Substitute the solution from step 1 into the other equation.

Step 3:

Solve this new equation.

Step 4:

Solve for the second variable.

Example 1: Solve the following system by substitution

2x+3yx+y=5=5

Solution:

Step 1: Solve one of the equations for either x = or y = . We will solve second equation for y.

x+yy=5=5−x

Step 2: Substitute the solution from step 1 into the second equation.

2x+3y2x+3(5−x)=5=5

Step 3: Solve this new equation.

2x+3(5−x)2x+15−3x−x+15−xx=5=5=5=5−15=10

Step 4: Solve for the second variable

yyy=5−x=5−10=−5

The solution is: (x, y) = (10, -5)

Note: It does not matter which equation we choose first and which second. Just choose the most convenient one first!

Example 2: Solve by substitution

2x+5y4x−y=12=2

Solution:

Step 1: Solve one of the equations for either x = or y =. Since the coefficient of y in equation 2 is -1, it is easiest to solve for y in equation 2.

4x−y−yy=2=2−4x=4x−2

Step 2: Substitute the solution from step 1 into the second equation.

2x+5y2x+5(4x−2)=12=12

Step 3: Solve this new equation ( for x ).

2x+5(4x−2)2x+2x+20x−1022xx=12=12=22=1

Step 4: Solve for the second variable

yyy=4x−2=4⋅x−2=2

The solution is: (x,y)=(1,2)

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.

answer: the answer is ann