# Southern New Hampshire University GZ - 8-2 Problem Set_ Module Eight.pdf

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10/18/2020Southern New Hampshire University - 8-2 Problem Set: Module Eight1/20[PRINT]MAT-140-J1898 20EW1 Precalculus, 8-2 Problem Set: Module Eight Geoffrey Zimmermann, 10/18/20 at 2:45:56 PM EDTQuestion1:Score 4/4 Solve the system of equations by any method.−2x+ 5y= − 217x+ 2y= 15Enter the exact answer as an ordered pair, (x,y)If there is no solution, enter NS. If there is an infinite number of solutions, enter the generalsolution as an ordered pair in terms of xInclude a multiplication sign between symbols. For example,a*x.Your response..
10/18/2020Southern New Hampshire University - 8-2 Problem Set: Module Eight2/207(−2x+ 5y)= 7(−21)Multiply both sides by 7.−14x+ 35y= − 147Use the distributive property.2(7x+ 2y)= 2(15)Multiply both sides by 2.14x+ 4y= 30Use the distributive property.Now, let’s add them.−14x+ 35y= − 14714x+ 4y= 3039y= − 117y= − 3For the last step, we substitute y= − 3into one of the original equations and solve for x.−2x+ 5y= − 21−2x+ 5(−3)= − 21−2x− 15= − 21−2x= − 6x= 3Our solution is the ordered pair (3, − 3). Check the solution in the original second equation.
10/18/2020Southern New Hampshire University - 8-2 Problem Set: Module Eight3/207x+ 2y= 157(3) + 2(−3)= 1521 − 6= 15TrueQuestion2:Score 4/4Solve the system of equations by any method.6x+ 11y= 15x+ 2y= 4Enter the exact answer as an ordered pair, (x,y).If there is no solution, enter NS. If there is an infinite number of solutions, enter the generalsolution as an ordered pair in terms of x.Include a multiplication sign between symbols. For example,a*x.Your responseCorrect response(-14,9)(-14,9)Auto gradedGrade:1/1.0 A+ 100% Total grade: 1.0×1/1 = 100%Feedback:In this case we use substitution.First, we will solve the second equation for x.
10/18/2020Southern New Hampshire University - 8-2 Problem Set: Module Eight4/20x+ 2y= 4x= − 2y+ 4Now we can substitute the expression −2y+ 4for xin the first equation.6x+ 11y= 156(−2y+ 4) + 11y= 15−12y+ 24 + 11y= 15y= − 9y= 9Now, we substitute y= 9into the second equation and solve for x.x+ 2(9)= 4x+ 18= 4x= − 14Our solution is (−14, 9).Check the solution by substituting (−14, 9)into both equations.
10/18/2020Southern New Hampshire University - 8-2 Problem Set: Module Eight5/206x+ 11y= 156(−14) + 11(9)= 15−84 + 99= 15Truex+ 2y= 4(−14) + 2(9)= 4−14 + 18= 4TrueQuestion3:Score 4/4Solve the system of equations by any method.