For lines to be perpendicular their slopes must be negative reciprocals of one another, mathematically:
m1*m2=-1, and in this case:
-m/4=-1
-m=-4
m=4, so the slope of the perpendicular line is 4 so we have thus far:
y=4x+b, using point (-4,3) we can solve for the y-intercept, "b"
3=4(-4)+b
3=-16+b
19=b, so our line is:
y=4x+19
In this math problem, we will be using rate of change.
850 naira’s / 20 mangoes
= 42.5 nairas for one mango.
Next, to find the cost of 15 mangoes, we will take the cost of our one mango and simply multiply it by 15.
= 42.5 nairas * 15
= 637.50 nairas
So, in conclusion, the cost of 15 mangoes is 637.50 naira.
Answer:

Step-by-step explanation:

Don't mind the 
Answer:
I got (1,2).
Step-by-step explanation:
Process of elimination:
Multiply the second equation by 3 to get same terms, subtract and solve for Y to get 2.
Plug 2 into second equation for Y to get x=1
(1,2)