Answer:
You have to eliminate one of the variables when the equations are added.
A) x + 2y + z = 10
B) 2x -y +3z = -5
C) 2x -3y -5z = 27
We mulutiply A) by 2 then add it to B and C
A) 2x + 4y + 2z = 20 and the sum =
6x = 42 Luckily, the "y" and "z" variables cancel out and we find:
x = 7
Then we use x =7 in calcucating equation A) and B)
A) 2y + z = 3
B) -y + 3z = -19
THEN solve for y and z by eliminating variables.
Step-by-step explanation:
Someone already made an answer for this
Answer:
3 grams
Step-by-step explanation:
We are going to take the mass of a bunch of little strips below the triangle "roof." To do this, we must figure out what formula for the mass we'll use, in this case, we'll use:
Mass of strip = denisty * area = (1+x)*y*deltax grams
now, because the "roof" of the triangle contains two different integrals (it completely changes direction), we will use TWO integrals!
**pretend ∈ is the sum symbol
Mass of left part = lim x->0 ∈ (1+x)*y*deltax = inegral -1 to 0 of (1+x)*3*(x+1) = 3 * integral -1 to 0 of (x^2 + 2x + 1) = 3 * 1/3 = 1
Mass of left part = lim x->0 ∈ (1+x)*y*deltax = inegral 0 to 1 of (1+x)*3*(-x+1) = 3 * integral 0 to 1 of (-x^2 + 1) = 3 * 2/3 = 2
Total mass = mass left + mass right = 1 + 2 = 3 grams
