18 less than 7 times a number is 80
Letter D
A = 135°
B = 30°
cosAcosB - sinAsinB = cos(A+B)
cos(135°+30°)
cos(165°)
Answer:
The solution is (0, 4)
Step-by-step explanation:
Please pay attention to the first two equations and drop the last two:
12x−5y=−20 y=x+4 x=x=x, equals y=y=y should ideally be:
12x−5y=−20
y=x+4
Let's find x. Substitute x + 4 for y in the first equation, obtaining:
12x - 5(x + 4) = -20
Carrying out the indicated multiplication, we get:
12x - 5x - 20 = -20, or 7x = 0
If x = 0 then y must be 0 + 4, or 4.
The solution is (0, 4)
Answer: x= -6
Let’s first rewrite the equation
3x-(2x-3)=2x+9
Now now distribute the -1•2x and the -1•-3
3x-2x+3=2x+9
Let’s now combine the like terms on the left side
x+3=2x+9
To get x alone on the left side, subtract it on both sides
3=x+9
To get your final answer, subtract 9 on both sides
-6=x
And that’s your answer for x! Hope this helps comment below for more questions :)