Solve each system by substitution

-4x + y = 6 () -5x + y = -2 () 3x - 8y = 24
-5x - y= 21 () -3x + 6y = -12 () -5x + y = -3

look, equation ii and vi are contradicting each other

Step-by-step explanation:

after eliminating those equation you can find the value of x and y.

y=-6

x=3

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1  

7 ft 6 in means 7 1/2, because 6 in is 1/2 of a foot. 7 ft 8 in means 7 2/3 because 8 in is 2/3 of a foot. 23/3 = 7 2/3. 15/2 = 7 1/2.

23/3   *   15/2   = 57 1/2

step-by-step explanation: