It depends on what variable you are tying to solve for first. Say you are trying to solve for x first and then y on the first problem you wrote.
In substitution you solve one of the equations for example with
6x+2y=-10
2x+2y=-10
you solve 2x+2y=-10 for x
2x+2y=-10
-2y = -2y (what you do to one side of the = you do to the other)
2x=-10-2y (to get the variable by its self you divide the # and the variable)
/2=/2 (-10/2=-5 and -2y/2= -y or -1y, they are the same either way)
x=-5-y
now you put that in your original equation that you didn't solve for:
6(-5-y)+2y=-10 solve for that
-30-6y+2y=-10 combine like terms
-30-4y=-10 get the y alone and to do this you first get the -30 away from it
+30=+30
-4y=20 divide the -4 from each side
/-4=/-4 (20/-4=-5)
y=-5
now the equation you previously solved for x can be solved for y.
x=-5-y
x=-5-(-5) a minus parenthesis negative -(- gives you a positive
-5+5=0
x=0
and now we have solved the problem. x=0 and y=-5
Answer:
2(Jill) - 20 + (Jill) = 205
3(Jill) = 225
(Jill) = 75
(Jack) = 2(75) - 20 => 150 - 20 = 130
Jill= 75
Jack= 130
Step-by-step explanation:
Answer:
Yes, they are proportional.
Step-by-step explanation:
Using this from what I found helped me answer the question, and if you compare their ratios, they are both going to show that 75% each class have texted:
Proportional: When quantities have the same relative size. In other words they have the same ratio.
All you would have to do is compare the amount of students that texted(x) to the amount of students there are total in the class(y). When you compare them in a y:x format, it will all lead up to the results showing that 75% of both groups have texted.
PART 1:55-21=35
35/60=<span>.58333
360</span>×<span>.58333 =210 DEGREES
</span><span>210*pi/180 = 3.665 RADIANS
PART 2: </span><span>(pi) x 2r x .58333
</span><span>3.14 x 12 x .58333 = 21.98 in
PART 3: </span><span>5π inches = 5 x 3.14 = 15.708 inches / 6 in radius = 2.618 radians
PART 4: </span><span>2.618 radians * 180/pi = 150° </span>
<span> x coordinate = 6(cos 150°) = -5.196 </span>
<span> y coordinate = 6(sin 150°) = 3 </span>
<span> the coordinates would be (-5.196, 2)</span>
