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Solve the system of linear equations by graphing. Round the solution to the nearest tenth as needed.

y + 2.3 = 0.45x

–2y = 4.2x – 7.8

(2.4, –1.2)

(–1, 2.5)

no solution

infinitely many solutions

Verified Answer :

texaschic101

y + 2.3 = 0.45x
y = 0.45x - 2.3

-2y = 4.2x - 7.8
-2(0.45x - 2.3) = 4.2x - 7.8
-0.90x + 4.6 = 4.2x - 7.8
-0.90x - 4.2x = -7.8 - 4.6
-5.1x = - 12.4
x = -12.4 / -5.1
x = 2.4

y + 2.3 = 0.45x
y = 0.45(2.4) - 2.3
y = 1.08 - 2.3
y = -1.2

solution is : (2.4, - 1.2)

y + 2.3 = 0.45x

y = 0.45x - 2.3


-2y = 4.2x - 7.8

-2(0.45x - 2.3) = 4.2x - 7.8

-0.90x + 4.6 = 4.2x - 7.8

-0.90x - 4.2x = -7.8 - 4.6

-5.1x = - 12.4

x = -12.4 / -5.1

x = 2.4


y + 2.3 = 0.45x

y = 0.45(2.4) - 2.3

y = 1.08 - 2.3

y = -1.2


solution is : (2.4, - 1.2)

Unfortunately, I can't do it on a graph here, but I will do it algebraically.

The solution on the graph will be the point of intersection of the two lines representing the equations.

y + 2.3 = 0.45x . . . . . (1)

-2y = 4.2x - 7.8 . . . . . (2)

From (2), y = 3.9 - 2.1x

substituting for y in (1), we have:

3.9 - 2.1x + 2.3 = 0.45x

2.55x = 6.2

x = 6.2/2.55 = 2.4

y = 3.9 - 2.1(2.4) = 3.9 - 5.04 = -1.2

Therefore, solution is (2.4, -1.2)



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