Answer:
X=31
Step-by-step explanation:
X-7+1+5x=180
6x-6=180
6x=180+6
6x=186
x=186÷6
X=31
Answer:
they are equal
Step-by-step explanation:
rectangle- 8 + 8 = 16
2 + 2 =4
rectangles perimeter is 20
square 5 X 4 = 20
sqaures perimeter is 20
Answer:
88.85 US$
Step-by-step explanation:
First, fint the roots of the equation
1.
![D=5^2-4\cdot 2\cdot (-7)=25+56=81,\\\sqrt{D}=\sqrt{81}=9,\\ \\x_1=\dfrac{-5-9}{2\cdot 2}=-\dfrac{14}{4}=-3.5,\\ \\x_2=\dfrac{-5+9}{2\cdot 2}=\dfrac{4}{4}=1.](https://tex.z-dn.net/?f=D%3D5%5E2-4%5Ccdot%202%5Ccdot%20%28-7%29%3D25%2B56%3D81%2C%5C%5C%5Csqrt%7BD%7D%3D%5Csqrt%7B81%7D%3D9%2C%5C%5C%20%5C%5Cx_1%3D%5Cdfrac%7B-5-9%7D%7B2%5Ccdot%202%7D%3D-%5Cdfrac%7B14%7D%7B4%7D%3D-3.5%2C%5C%5C%20%5C%5Cx_2%3D%5Cdfrac%7B-5%2B9%7D%7B2%5Ccdot%202%7D%3D%5Cdfrac%7B4%7D%7B4%7D%3D1.)
2. You can see that this equation has two different real roots. Note that you can make this statement without finding roots, only knowing the value of discriminant: since D=81>0, then the equation has two different real roots.