Answer: x = 3 and y = 10
Step-by-step explanation:
-8x + 5y = 26 .................. equation 1
9x - 3y = -3 ................ equation 2
Solving the system of linear equations by elimination method.
The means we have to make the coefficient of one of the variable the same in order to eliminate the variable first.
Let us eliminate the variable y first , this means we will multiply equation 1 by 3 and multiply equation 2 by 5. Doing this , we have
-24x + 15y = 78 ............. equation 3
45x - 15y = -15 ................ equation 4
Now that we have the same coefficient , we have to check their signs , if the have the same signs , we will subtract , that is , if both are having positive signs , we will subtract , if both have negative signs , we will also subtract but if their signs differ we will add. Following this rule and considering the equations above , the coefficients of y have different signs , so we will add equation 3 and equation 4 , so we have:
21x = 63
x = 63/21
x = 3
Substitute x = 3 into equation 1 or equation 2 to get the value of y , using equation 2 , we have
9x - 3y = -3
9(3) - 3y = -3
27 - 3y = -3
27+3 = 3y
30 = 3y
30/3 = y
Therefore y = 10
Therefore : x = 3 and y = 10
pounds of that
copper alloy:
.
pounds of that
copper alloy:
.