Hope you could understand.
If you have any query, feel free to ask.
ANSWER -
-1
EXPLANATION - any expression multiplied by 1 remains the same
28x + 44y = 964.40
21x + 33y = 723.30
Let's multiply the first equation by 4 and the second by -4
84x + 176y = 3857.6
-84x - 132y = -2893.2
Add the equations together.
0 + 44y = 964.4
Simplify
44y = 964.4
Divide both sides by 44
y = 964.4/44
Since we have the value of y, let's plug 964.4/44 into y for the first equation.
28x + 44(964.4/44) = 964.40
Simplify the left side
28x + 964.4 = 964.4
Subtract 964.4 from both sides
28x = 0
Divide both sides by 0
x = 0
In conclusion,
y = 964.4/44
x = 0
Answer:
c. When gives tow names for the same quantity, you can use algebra to solve the equation.
Hope it help you
Try this solution (see the attachment), note:
1. the word 'ctgx' means 'cotangens x'; 2. this equation has roots not for all the real number 'r', it is shown in the 2-d line of the answer; 3. the answer is marked with red colour.