The first one, SAS Postulate
Answer:
13.
Let us say
first angle be = 4x -10
second angle = x
now add them to 90 as complementary angles add up to 90
4x - 10 + x = 90
5x - 10 = 90
5x = 90+10
5x = 100
x = 100/5
x = 20
the first angle = 4x -10
= 4(20) -10
= 80 -10
= 70
the second angle = x
= 20
the angles are 70 and 20
X+8
2x
x-3
8 more hours
twice the number
3 years younger
The general formula for a equation of the form:
is:
![x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%7D%7B2a%7D)
In this case we notice that a=1, b=-4 and c=3. Plugging this values in the general formula we get:
![\begin{gathered} x=\frac{-(-4)\pm\sqrt[]{(-4)^2-4(1)(3)}}{2(1)} \\ =\frac{4\pm\sqrt[]{16-12}}{2} \\ =\frac{4\pm\sqrt[]{4}}{2} \\ =\frac{4\pm2}{2} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20x%3D%5Cfrac%7B-%28-4%29%5Cpm%5Csqrt%5B%5D%7B%28-4%29%5E2-4%281%29%283%29%7D%7D%7B2%281%29%7D%20%5C%5C%20%3D%5Cfrac%7B4%5Cpm%5Csqrt%5B%5D%7B16-12%7D%7D%7B2%7D%20%5C%5C%20%3D%5Cfrac%7B4%5Cpm%5Csqrt%5B%5D%7B4%7D%7D%7B2%7D%20%5C%5C%20%3D%5Cfrac%7B4%5Cpm2%7D%7B2%7D%20%5Cend%7Bgathered%7D)
then:
and
Therefore, x=3 or x=1.
