Answer:
11
Step-by-step explanation:
The two equations appear to be ...
- 12x +4y = 152
- 32x +12y = 420
These can be solved for y using Cramer's rule:
y = (152(32) -420(12))/(4(32) -12(12)) = -176/-16 = 11
The cost of the vegetarian lunch is 11.
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<em>Comment on Cramer's Rule</em>
For equations ...
ax +by =c
dx +ey = f
The solutions are ...
x = (bf -ey)/(bd -ea)
y = (cd -fa)/(bd -ea) . . . . note the denominators are the same expression
Once you memorize the pattern of products, this can be the simplest way to solve a pair of equations--especially if you only need one of the variable values.
Answer:
B) only (-3 , 3)
Step-by-step explanation:
y = -3x - 6
(-4,4) y = -3 x (-4) - 6 = 12 - 6 = 6 .... incorrect
(-3,3) y = (-3) x (-3) - 6 = 9 - 6 = 3 ..... correct
I'm really sorry, I'm not the best at this, but I did all the equations the best to my knowledge and came up with these 3 answers
(2,-1) which equaled -7
(5,4) which equaled -11
and (0,-9) which equaled - 9
Again I'm really sorry if this didn't work. :( God bless and good luck with future lessons.