Lesson 3 Unit 7, Solving Systems Using Elimination Quiz 1. (I'VE ALREADY ANSWERED THIS)2. What is the solution of the system?7x + 5y = 19-7x - 2y = -16(A). (2, 1)(B). (1, 2)(C). (7, 5)(D). (-7, -2)3. Which method would be the simplest way to slove the system?y = 1/2x2x + 3y = 28 (A). Graphing(B). Substitution (C). Elimination (D). Distributive 4. What is the solution of the system? y = -3x3x + 2y = 6(A). (2, 6)(B). (-1, 3)(C). (-2, 6)(D). (1.5, -4.5)5. How many solutions does this system have?-3x + 6y = 10-3x + 6y = -4(A). None (B). One (C). Infinite (D). Two6. In wich quadrant does the solution of the system fall?y = x - 1y = -3x - 5(A). I(B). II(C). III(D). IV

Answer:2) A3) B4) C5) A6) CStep-by-step explanation:2) Lets add 2 equation together, we will find:[tex]7x-7x+5y-2y=19-16\\3y=3\\y=1[/tex]If we put y value in the first equation:[tex]7x+5=19\\7x=14\\x=2[/tex]It is A3) Substation is the best way to solve the system.Lets multiply first equation with 4:[tex]4y=2x[/tex]Substitute 2x with 4y:[tex]4y+3y=28\\y=4[/tex]and x=84) Again lets substitute 3x with -y:[tex]-y+2y=6\\y=6[/tex]Therefore x=-2Correct answer is C5) None of real numbers is the solution of this system.6) First lets multiply first equation with -1 and add equations together:[tex]y-y=-3x-x-5+1\\0=-4x-4\\x=-1\\y=-2[/tex]It falls to IIIThe answer is C