Bosco

I misread the problem and made a mistake

Find the values of $a$ such that $ax^2+15x+4-12x+5$ is the square of a binomial.    

                                              ax^2+15x+4-12x+5    

Combine like terms                ax² + 3x + 9    

For this to be a square    

then b² – 4ac must = 0          3² – (4)(a)(9)  =  0    

                                                        9 – 36a  =  0           

                                                              36a  =  9    

                                                                   a  =  0.25    

The problem doesn't ask for      

the binomial, but it's (0.5x + 3)    

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Keddy and Jacob saved the same amount of money. Jacob spent $144 buying a birthday gift for his friend. In the end, Keddy had 4 times as much as Jacob. How much did Keddy have?   

                              K  =  J   

                              K  =  4 • (J – 144)   

                               K  =  4 • (J – 144)   

K = J   therefore      J   =  4 • (J – 144)   

                                J  =  4J – 576    

                            576  =  3J    

                                 J  =  192   

K = J  therefore        K  =  192    

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Factor

                                                (r – 4)(r – 1)      (r – 5)(r + 3)   

                                                ––––––––––  =  ––––––––––    

                                                (r – 7)(r – 1)      (r – 5)(r + 4)    

Cancel (r – 1) and

Cancel (r – 5)    

                                                          (r – 4)      (r + 3)   

                                                           –––––  =  –––––    

                                                          (r – 7)      (r + 4)    

Cross multiply   

                                                  (r – 4)(r + 4)  =  (r – 7)(r + 3)   

                                                           r² – 16  =  r² – 4r – 21         

Subtract r² from both sides and

Combine like terms  

                                                               – 16  =  – 4r – 21         

                                                                   4r  =  – 5    

                                                                     r  =  – 1.25    

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Before I'd even attempt to tackle this, I'd have to see some parentheses. 

For example, is that first one supposed to be a^(2•b) = 1 or (a²)•b = 1   

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