2a+1b=27.50
4a+2b=59.50
Multiply first equation by -4 and the second by 2 so you can drop off the a values then add the equations together. Then solve for b. You should get b=6.
Then plug b into one of the original equations and solve for a and you should get 10.75
So a plate of spaghetti is $10.75 and a salad is $6.
<em><u>Please mark brainliest!</u></em>
68 divided by 85 multiply by 100
68/85=0.8 x 100= 80%
You're solving a system here, easy peasy. Solve the second equation for y to get y = 2 - 3x. Now in the first equation, sub in this y value where you see a y and now the equation is in terms of x only: x^2 + (2-3x)^2 = 20. You have to FOIL out the (2-3x)^2 first to get x^2 + 4 - 12x + 9x^2 = 20. Now combine like terms to get 10x^2 - 12x + 4 = 20. Move the 20 over by subtraction to get
10x^2 - 12x - 16 = 0. Factor this now, taking a 2 out first: 2(5x^2 - 6x -8)=0 and you get factors of 2(x-2)(5x+4)=0. x=2 or x = -4/5. If x = 2, then y = -4. If x = -4/5, then y = 22/5
