Answer:
r = 4
General Formulas and Concepts:
<u>Pre-Alg</u>
- Order of Operations: BPEMDAS
- Equality Properties
Step-by-step explanation:
<u>Step 1: Define equation</u>
-5 + 22 = r - 4 + 3r + 5
<u>Step 2: Solve for </u><em><u>r</u></em>
- Combine like terms: 17 = 4r + 1
- Subtract 1 on both sides: 16 = 4r
- Divide 4 on both sides: 4 = r
- Rewrite: r = 4
<u>Step 3: Check</u>
<em>Plug in r to verify it's a solution.</em>
- Substitute: -5 + 22 = 4 - 4 + 3(4) + 5
- Add/Subtract: 17 = 3(4) + 5
- Multiply: 17 = 12 + 5
- Add: 17 = 17
Answer:
3526
Step-by-step explanation:
4300×3%=129
129×6=774
4300_774= 3526
Some sets of three are collinear
We have an isosceles triangle;
A=opposite angle side a.
B=opposite angle side b.
C=opposite angle side c.
A=B
Method 1:
We can divide the isosceles triangle in two right triangles,
hypotenuse=7
side=9/2=4.5
B=A=arccossine (4.5/7)=49.994799...º≈50º
C/2=90º-50º=40º ⇒ C=2*40º=80º
Answer:
a=7; A=50º
b=7; B=50º
<span>c=9; C=80º
Method 2:
Law of cosines:
a²=b²+c²-2bcCosA ⇒CosA=(a²-b²-c²)/(-2bc)
CosA=(49-49-81) / (-126)=0.642857
A=arco cos (81/126)≈50º
B=A=50º
A+B+C=180º
50º+50º+C=180º
C=180º-100º
C=80º
Answer:
</span>a=7; A=50º
b=7; B=50º
<span>c=9; C=80º</span>
