Answer:
Yes
Step-by-step explanation:
Because 9, 12, and 15 are Pythagorean triples
Answer:
-12
Step-by-step explanation:
Just sustitute the z for -4
z+z+z
-4+(-4)+(-4)
=-12
I hope this help :)
Last one 9 46/180
It's actually pretty basic
Answer:

Step-by-step explanation:
So we have the system of equations:

And we want to multiply the first equation by some constant such that the resulting equation matches the coefficient of [x] in the second equation.
We can see that the coefficient of x in the second equation is 15.
So, to match 15, we must multiply the first equation by 3. So:

Multiply:

And we're done!