9x – 3y – 5x + 7y + x + y
9x-5x+x -3y+7y+y
x(9-5+1) +y(-3+7+1)
5x+5y
Choice C
Sample Equation: 3x - 3 = 27
Multiple step:
3x - 3 = 27
<u> + 3 +3</u> Step1. Remove the -3 by adding 3 to both sides
3x = 30
<u>÷3 ÷ 3</u> Step2. Remove the multiplicand 3 by dividing both sides by 3
x = 10
To check: substitute x by its value
3x - 3 = 27
3(10) - 3 = 27
30 - 3 = 27
27 = 27
Answer:
Check the proof below
Step-by-step explanation:
try to verify from RHS to LHS
(Tan a + tan b) / (tan a - tan b)
= (sin a / cos a + sin b /cos b) / ( sin a/ cos a - sin b/ cos b)
= (sin a cos b + cos a sin b)/ (sin a cos b - cos a sin b)
= sin (a+b) / sin (a-b)
Fyi
sin(A+B) = sinAcosB+cosAsinB
sin(A-B) = sinAcosB-cosAsinB
