Answer:
Step-by-step explanation:
The angles labeled 4y - 8 and 79 + y are called vertical angles, and definition, vertical angles are congruent. That means algebraically, that
4y - 8 = 79 + y and
3y = 87 and
y = 29
x + y = 3.36 --> the boys are splitting $3.36
x = 3y - .12 --> one boy received $.12 less than 3 times as much as the other
--> substitute the second equation for the x in the first equation
(3y - .12) + y = 3.36 --> combine like terms
4y - .12 = 3.36 --> add .12 to both sides of the equation
4y = 3.48 --> divide both sides by 4
y = .87
the other boy gets $0.87
substitute into x = 3y - 12
x = 3(.87) - .12
x = 2.61 - .12
x = 2.49
the first boy gets $2.49
Answer:
the first one its true
y of A greater than the y of B
You cannot add row 2 to column 3 because they have different dimensions. You can do any of the other operations, but the only one that makes any sort of sense is ...
Multiply row 2 by -1 and add it to row 3
_____
It makes no sense to multiply a row by zero. That makes the entire row zero and makes the matrix useless for finding any sort of solution.
You can switch columns, but that doesn't get you any closer to a solution here.
If I were trying to find a solution, I might
switch rows 1 and 2
multiply the new row 1 by -3 and add it to the new row 2
multiply the new row 1 by 2 and add it to row 3
This sequence of operations will make the first column [1 0 0], reducing the problem to 2×2 from 3×3.
