Answer:
A) z= -4
Step-by-step explanation:
<span> tan(x)/ cos(x)-sec(x)
tanx/(cosx-1/cosx)
tanx/cos^2x-1)--------------------1-sin^2x=cos^2x
-tanx/sin^2x
-(sinx/cosx)/sin^2x
-1/sinxcosx
multiply 2/2
-2/2sinxcosx-------------sin2x=2sincosx
-2/sin2x------------------1/sinx=cosecx
-2cosec2x</span>
Answer:
(3, -6)
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality<u>
</u>
<u>Algebra I</u>
- Coordinates (x, y)
- Terms/Coefficients
- Solving systems of equations using substitution/elimination
Step-by-step explanation:
<u>Step 1: Define Systems</u>
y = 4x - 18
y = -5x + 9
<u>Step 2: Solve for </u><em><u>x</u></em>
<em>Substitution</em>
- Substitute in <em>y</em> [2nd Equation]: 4x - 18 = -5x + 9
- [Addition Property of Equality] Add 5x on both sides: 9x - 18 = 9
- [Addition Property of Equality] Add 18 on both sides: 9x = 27
- [Division Property of Equality] Divide 9 on both sides: x = 3
<u>Step 3: Solve for </u><em><u>y</u></em>
- Substitute in <em>x</em> [1st Equation]: y = 4(3) - 18
- Multiply: y = 12 - 18
- Subtract: y = -6
Step-by-step explanation:
0.4 x + 3.9 = 5.7
hope 0.4 x = 5.78 - 3.9
0.4x = 1.88
x = 1.88/0.4
x = 4.7