How do you do this equation? solve simultaneous equations by substitution
2x + 3y = 7
2x + 7y = 19

(- 1, 3 )

Step-by-step explanation:

Given the 2 equations

2x + 3y = 7 → (1)

2x + 7y = 19 → (2)

In (1) subtract 3y from both sides

2x = 7 - 3y → substitute into (2)

7 - 3y + 7y = 19

7 + 4y = 19 ( subtract 7 from both sides )

4y = 12 ( divide both sides by 4 )

y = 3

Substitute y = 3 into either of the 2 equations and solve for x

Substituting into (1)

2x + 3(3) = 7

2x + 9 = 7 ( subtract 9 from both sides )

2x = - 2 ( divide both sides by 2 )

x = - 1

solution is (- 1, 3 )

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk