The value of the number is 80,000
Y = -10x + 1...slope here is -10. A perpendicular line will have a negative reciprocal slope. To find the negative reciprocal of a number, flip the number and change the sign. So our perpendicular line will need a slope of 1/10.
y = mx + b
slope(m) = 1/10
(5,7)....x = 5 and y = 7
now sub and find b, the y int
7 = 1/10(5) + b
7 = 1/2 + b
7 - 1/2 = b
14/2 - 1/2 = b
13/2 = b
so ur perpendicular line going thru (5,7) is y = 1/10x + 13/2
Answer: B (2,1)
You know what y is (x-1) so you substitute that for y in the other equation.
3x+ ((4)(x-1))=10
3x+4x-4=10
7x=14
x=2
Then put x=2 into y=x-1
y=2-1
y=1