The first sentence → x - 2y = -1
the second one → 3x - 2y = -3
multiply the first one by -1
you can get → -x + 2y = 1
plus two sentences together
you can get → 2x = -2
so you are able to know that x = -1
and y = 0
<span>If x= side of the square, and A = area of square, then
A = x^2
dA/dx = 2x, or
dA = 2x*dx, where dx is the differential in x (same as error)
dA/A = 2x*dx/(x^2) = 2*dx/x = 2*(0.05cm)/(15cm) = 0.00667 = 0.667%
for b):
if dA/A = 0.025 = 2*dx/x, then
dx/x=(0.025)/2 = 0.0125 = 1.25 %
I hope I helped. :)</span>
Answer:
x=5,y=5,z=5
Step-by-step explanation:
x=15-y-z
15-y-z-y+z=5
15-2y=5
y=5
x+y+z=15
15-2y+y+z=15
15-10+5+z=15
z=5
x-y+z=5
x-5+5=5
x=5
Quadratic is in the form
ax^2+bx+c=0
so distribute and stuff and simplify
remember
a(b+c)=ab+ac
(x+2)^2+5(x+2)-6=0
remember order of opertaions
(x+2)(x+2)+5(x+2)-6=0
x^2+4x+4+5x+10-6=0
add like terms
x^2+9x+8=0
