A student is trying to solve the system of two equations given below: Equation P: y + z = 6 Equation Q: 3y + 4z = 1 Which of the following is a possible step used in eliminating the y-term?
is this type a typed answer?
(y + z = 6) ⋅ 4 (3y + 4z = 1) ⋅ 4 (y + z = 6) ⋅ −3 (3y + 4z = 1) ⋅ 3
To eliminate a variable, you need to add the equations or multiples of the equations in which the same variable in both equations will add to zero.
In order to elminiate any term from an equation when you have multiple equations .. U've to multiply one with the first equation that will result in a "zero" when you add them up ... In Ur case, this would be the third choice :D Let me know if U got it :)
oh i get it that makes sence
You want to eliminate y. The second equation has 3y. If you could change the first equation to have -3y, that would do it. Does any choice change the first equation so that the y term becomes -3y?
sorry I meant to multiply by a constant factor :)
ya thats what i try but i kept getting stuck
can u guys help me out with one more
Feel free :D
A set of equations is given below: Equation E: c = 2d + 1 Equation F: c = 3d + 7 Which statement describes a step that can be used to find the solution to the set of equations? Equation F can be written as c = 3(c − 1) + 7. Equation F can be written as c = 2(c − 7) + 1. Equation F can be written as d + 1 = 3d + 7. Equation F can be written as 2d + 1 = 3d + 7.
Just find d in term of c from Equation E and then plug the value in the other equation or find c in terms of d and do same steps :)
Let's try to get c in terms of d .. To do so, U've to get c in one hand and d on the other hand in one of the equations let's say equation E .. we already have that done for us .. then plug c in equation F and see if any of the answers is what we have got
Second problem. Look at the given equations. Notice they are both solved for c. Set them equal to each other. If c = 2d + 1 and c = 3d + 7, then 2d + 1 must equal 3d + 7 Which choice shows this?
If none of them is what we got .. Then we are now sure that the answer contains no d's ! So we try the other way .. Try to get d in terms of c from Equation E and plug it in equation F as well as what we have did in the last step for c in terms of d
The answer is D
Replace the c of equation F with 2d + 1, since from equation E we know that c = 2d + 1. Answer is choice D.