Answer:
x=51
Step-by-step explanation:
There are two ways you can go about this
You can either say that the sum of interior angles in a triangle is equal to 180 so you do 180-39-90=51
Or you could use the exterior angle theorem, which means that 90=39+x, simplify that and you get that x=51
I'll go with graphing cause when you try graphing a picewise function for example it's much harder to graph because it's to many numbers and you can't figure out what to graph especially for me.) mark me brainliest please
15x^2 = 12x
divide each side by x
15x = 12
now divide each side by 15
x = 12/15 or 4/5 which is also 0.8