Exercise 17 Page 203

We want to solve a system of linear equations using a graphing calculator. First, notice that we need to rewrite the equations into slope-intercept form so that we can write the functions in the calculator. Let's do it! We know that the solution to the system of linear equations is the point of intersection of the graphs of the equations. We can find the point of intersection on the calculator by pushing 2nd and CALC, then choosing the fifth option, intersect.

We know that the solution to the system of linear equations is the point of intersection of the graphs of the equations. We can find the point of intersection on the calculator by pushing 2nd and CALC, then choosing the fifth option, intersect.

The graphs intersect at the point (-6,2). Finally, we have to check whether this point is a solution to the system of equations. Let's substitute -6 for x and 2 for y in each equation and check if they create true statements.

-1.1x-5.5y=-4.4 & (I) 0.8x-3.2y=-11.2 & (II)

SubstituteII

x= -6, y= 2

-1.1( -6)-5.5( 2)? =-4.4 0.8( -6)-3.2( 2)? =-11.2

Multiply

(I): Multiply

6.6-11? =-4.4 0.8(-6)-3.2(2)? =-11.2

SubTerm

(I): Subtract term

-4.4=-4.4 ✓ 0.8(-6)-3.2(2)? =-11.2

Multiply

(II): Multiply

-4.4=-4.4 ✓ -4.8-6.4? = -11.2

SubTerm

(II): Subtract term

-4.4=-4.4 ✓ -11.2=-11.2 ✓

Both equations resulted in a true statement, so we know our answer is correct. We found that the solution to the system of equations is (-6,2).