Question

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

Answer 1

x=2.30=2(approx)

Step-by-step explanation:

First we consider ,y+2.3=0.45x-2y

                            3y=0.45x-2.3.............(1)

Now, we take y+2.3=4.2x-7.8

                       y+2.3+7.8=4.2x

                       y+10.1=4.2x.............(2)

Multiply by 3 in eq.2)

3y+30.3=12.6x............(3)

Subtract 3) from 1)

3y-(3y+30.3)=0.45x-2.3-(12.6x)

3y-3y-30.3=0.45x-2.3-12.6x

-30.3=-12.15x-2.3

-30.3+2.3=-12.15x

28=12.15x

x=28/12.15

x=2.30=2(approx)

Similarly ,y can be find.

Answer 2

Given: Two equation $y+2.3=0.45x-2y$ and $y+2.3=4.2x-7.8$

To Find: Find the value of $x$.

Step-by-step explanation:

Two equation $y+2.3=0.45x-2y$ and $y+2.3=4.2x-7.8$__1

∴  $y+2.3=0.45x-2y$

⇒$3y=0.45x-2.3$

⇒$y=\frac{0.45}{3}x-\frac{2.3}{3}$

⇒$y=0.15x-0.77$

Plug the $y$ value in equation-1,

∴ $0.15x-0.77+2.3=4.2x-7.8$

⇒$4.2x-0.15x=7.8-0.77+2.3$

⇒$4.05x=9.33$

⇒$x=\frac{9.33}{4.05}$

∴ $x=2.30$

In the given diagram $x$ value also same.

So, The value of $x$ is $2.30$.