When two lines intersect to form a 90 degree angle, these lines are called perpendicular lines.
7x^2 - x = 6
7x^2 - x - 6 = 0
(7x + 6 )(x - 1) = 0
7x + 6 = 0; x = -6/7
x - 1 = 0; x = 1
answer
x = -6/7; x = 1
You'll have to solve simultaneously
let nickel be x, dime be y
x + y = 35 ... ( 1 )
5x + 10 y = 250
5 ( x + 2y ) = 250
x + 2y = 50 ... ( 2 )
in ( 1 )
x = 35 - y ( 3 )
sub ( 3 ) into ( 2 )
( 35 - y ) + 2y = 50
y = 15
sub y into ( 1 )
x + y = 35
x + 15 = 35
x = 20
therefore, Sandy has 20 nickels and 15 dimes
Any line can be expresses as:
y=mx+b where m=slope=(y2-y1)/(x2-x1) and b=y-intercept (value of y when x=0)
First find the slope:
m=(2-0)/(8-0)=2/8=1/4 so we have thus far:
y=0.25x+b, we solve for b using any point on the line, (8,2)
2=0.25(8)+b
2=2+b
0=b
So the line is:
y=.25x which they might also express as y=x/4
The answer is E. (1/4)x
