Cos = adjacent / hypotenuse
cos B = 4/5
B = cos^-1 (4/5)
B = 36.869897....
B = 36.87° (nearest hundredth)
Angle B = 36.87°.
Ans n solution can refer in the picture
2x + 4(x - 1) = 2 + 4x
2x + 4x - 4 = 2 + 4x
6x - 4 = 2 + 4x
6x - 4x = 2 + 4
2x = 6
x = 3........there is 1 solution
25 - x = 15 - (3x + 10)
25 - x = 15 - 3x - 10
25 - x = -3x + 5
3x - x = 5 - 25
2x = - 20
x = -20/2
x = -10.....there is 1 solution
4x = 2x + 2x + 5(x - x)
4x = 4x + 5x - 5x
4x = 4x......this has infinite solutions
learn this...
if ur equation ends in a variable equaling a number, then there is one solution.
if ur equation ends in something not equal, like 2 = 4, or 4 = 6, then there is 0 solutions.
if ur equation ends in something equal to something,(the same) like 2 = 2, or 4x = 4x, then there is infinite solutions
Answer:
this is not a full question
Step-by-step explanation:
Answer:
7. r = -5
8. x = -1
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
Step-by-step explanation:
<u>Step 1: Define</u>
r + 2 - 8r = -3 - 8r
<u>Step 2: Solve for </u><em><u>r</u></em>
- Combine like terms: -7r + 2 = -3 - 8r
- Add 8r to both sides: r + 2 = -3
- Subtract 2 on both sides: r = -5
<u>Step 3: Check</u>
<em>Plug in r into the original equation to verify it's a solution.</em>
- Substitute in <em>r</em>: -5 + 2 - 8(-5) = -3 - 8(-5)
- Multiply: -5 + 2 + 40 = -3 + 40
- Add: -3 + 40 = -3 + 40
- Add: 37 = 37
Here we see that 37 does indeed equal 37.
∴ r = -5 is a solution of the equation.
<u>Step 4: Define equation</u>
-4x = x + 5
<u>Step 5: Solve for </u><em><u>x</u></em>
- Subtract <em>x</em> on both sides: -5x = 5
- Divide -5 on both sides: x = -1
<u>Step 6: Check</u>
<em>Plug in x into the original equation to verify it's a solution.</em>
- Substitute in <em>x</em>: -4(-1) = -1 + 5
- Multiply: 4 = -1 + 5
- Add: 4 = 4
Here we see that 4 does indeed equal 4.
∴ x = -1 is a solution of the equation.
