I need some help understanding how to solve these problems, could I get some assistance?

8. [-/1 Points] DETAILS Use the inverse matrix to solve the system of linear equations. x - 2y = 3 2x - 3y = 9 ( x, V ) = Need Help? Read It Watch It Submit Answer 9. [-/1 Points] DETAILS 1 1 -1 Use the inverse matrix -3 2 -1 to solve the system of linear equations. 3 -3 2 x+y+ z=1 3x + 5y + 4z = 9 3x + 6y + 5z = 8 ( x , y, Z) =12. [-/1 Points] DETAILS MY NOTES ASK YOUR TEACHER PRACTICE ANOTH Use the matrix capabilities of a graphing utility to solve the system of linear equations, if possible. (If there is no solution, enter NO SOLUTION. If the system is dependent, set z = a and solve for x and y in terms of a.) 2x + 3y + 52 = 48 3x + 5y + 92 = 86 5x + 9y + 17z = 162 ( x, y, z ) = ( Need Help? Read It Watch It 13. [-/1 Points] DETAILS MY NOTES ASK YOUR TEACHER PRACTICE ANOTH You invest in AAA-rated bonds, A-rated bonds, and B-rated bonds. The average yields are 4.5% on AAA bonds, 5% on A bonds, and 9% on B bonds. You invest twice as much in B bonds as in A bonds. Let x, y, and z represent the amounts invested in AAA, A, and B bonds, respectively. * + y + z = (total investment) 0.045x + 0.05y + 0.09z = (annual return) 2y - Z = 0 Use the inverse of the coefficient matrix of this system to find the amount invested in each type of bond for the given total investment and annual return. (Round your answers to the nearest cent.) Total Investment Annual Return $12,800 $835 amount invested in AAA-bonds LO amount invested in A-bonds amount invested in B-bonds2. [-/1.05 Points] DETAILS Show that B is the inverse of A. A= To show that B is the inverse of A, we need to show that AB = I = BA. 2 AB = W/ H -1 -10 0 -1 - 1 ( 4 ) + + (-2) (-4) + + (8) (-4) + + (14) = W / H + (2 ) + (-3) + (-8) + (12) + (-20) + (21) (0) + (-1) + (0 ) + (4 ) + (0) + (10) + = - 4 BA = 1 -4 -1 2 w -1 4 0 -1 -1 (4 ) + + (0) (-1) + + (-1) (-2) + + (-1) = w / H + (4) + (0) + (-8) + (10) + (-12) + (10) (4 ) + (-4 ) + (-1) + (8) + (-2) + (12) + =