Answer
Top one
Step by step explanation
Let a = x^2 and b=y^2
a-b=7
4a+b=73
4(7+b)+b=73 5b=45 b=9
a=7+b = 7+9 = 16
Then
x^2=16, x=+-4
y^2=9, y=+-3
Answer to problem 1 is {-144,-192}
Answer to problem 2 is {-12,-12}
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Explanation:
Vector u is given to be u = {-18,-24}
To compute the vector 8*u, we multiply both sides by 8 and multiply each coordinate by 8
The rule I'm using is if u = (a,b) then k*u = (k*a,k*b)
So,
u = {-18,-24}
8*u = 8*{-18,-24}
8*u = {8*(-18),8*(-24)}
8*u = {-144,-192}
Problem 2 is handled the same way
f = {-2,-2}
6*f = 6*{-2,-2}
6*f = {6*(-2),6*(-2)}
6*f = {-12,-12}
b is correct Step-by-step explanation: i took the test