it says "use the inverses found in Problems 29-38 to solve each system of equations"(not sure what it means by that)(adsbygoogle = window.adsbygoogle || []).push({});

pg742,#47)

2x+y= -3

ax+ay=-a

a≠0 <----a≠0 was already in the book next to the equation

the book says the answer is x=-2,y=1

-what i have so far-

[2 1] [-3] --> (2 x a)-(a x 1) = 1a

[a a]=[-a]

[a -1]

A^-1= 1/det(A) x [-a 2]

[a -1] [1 -1/a]

A^-1= 1/1a x [-a 2] = [-1 2/a] <---inverse

[x] [1 -1/a] [-3]

[y] = [-1 2/a] [-a]

50) bx+3y= 14

bx+2y=10

b≠0 <------b≠0 was already in the book next to the equation

My math book is called "Precalculus seventh edition Sullivan", its a dark green/blue color(just in case you might have it). on pg 742 it says "show that each matrix has no inverse"

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# Homework Help: Pre Calc, how to you solve an equation if it says a≠0? please help!

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