12x - 8y = -12
6x + 4y = -30
Multiply the 2nd equation by 2, to make the Y coefficients opposite:
6x + 4y = -30 x 2 = 12x + 8y = -60
Now add the two equations:
12x -8y = -12 + 12x +8y = -60
= 24x = -72
Divide bothe sides by 24 to solve for x:
x = -72/24
x = -3
Now replace x with -3 in the first equation to solve for y:
12(-3) - 8y = -12
-36 - 8y = -12
Add 36 to each side:
-8y = 24
Divide both sides by -8 to solve for y:
y = 24 / -8
y = -3
X = -3 and y = -3
(-3,-3)
0.9 ..............................
Answer - D.
you basically find the equation of the line first and eliminate the wrong answers...
Strategy: before u do any of this, label your coordinates as (X1,Y1) and (X2,Y2) and u can choose any of ur points to be as x1 or x2 or y1 or y1...
basically, I'll choose (6,7) as (x1,y1) and (2,-1) as (x2,y2). SO,
First you have to find the gradient (m) of the line.
you do this by using the formula m = Y2-Y1 / X2-X1 (where '/' is division sign) ....
Put the numbers in their respective places and your gradient will be 2x. we put the x after our number to represent it as a gradient as the straight line formula is y = mx+c and you've found the m.
NOW.
use the formula Y-Y1=m(x-x1) to find the equation of the line.Again u can use any Y1 and X1 here but remember your m is 2
replace the digits and solve...Hopefully you'll get sth like this if you use the points (6,7):
Y-7 = 2(x-6) ....
y=2x-12+7...
Y=2x-5! <<<< this is your straight line equation!
Now all u gotta do is rearrange all your options into y = mx+c.
D. is incorrect as it gives us y=2x+5 and not y = 2x-5 unlike the others
Hope you get it!
Answer:
150
Step-by-step explanation:
-(-4)^2 + 7(-2)^4 - 2(-3)^3
-16 + 112 - 2(-27)
; -16 + 112 + 54
;150
