Step-by-step explanation:
Exercícios:
9. Sobre o estudo de equações, escreva V para as afirmações verdadeiras e F para as falsas.
a) ( ) A expressão 17 - 4x + 25 representa uma equação.
b) ( ) O número 23 representa um dos membros da equação -9x + 4 = 23.
c) ( ) Na equação x + 4 = 3x + 20, a incógnita é x.
d) ( ) A equação 3y - 15 = 0 não tem segundo membro.
67% of 1280 is 857.6 substrack it and it's = 422.4
Answer:
24/25
Step-by-step explanation:
Step 1: Define systems of equation
10x - 16y = 12
5x - 3y = 4
Step 2: Rewrite one of the equations
5x = 4 + 3y
x = 4/5 + 3y/5
Step 3: Solve for <em>y</em> using Substitution
- Substitute 2nd rewritten equation into 1: 10(4/5 + 3y/5) - 16y = 12
- Distribute the 10 to both terms: 40/5 + 30y/5 - 16y = 12
- Simplify the fractions down: 8 + 6y - 16y = 12
- Combine like terms (y): 8 - 10y = 12
- Subtract 8 on both sides: -10y = 4
- Divide both sides by -10: y = 4/-10
- Simply the fraction down: y = -2/5
Step 4: Substitute <em>y</em> back into an original equation to solve for <em>x</em>
- Substitute: 5x - 3(-2/5) = 4
- Multiply: 5x + 6/5 = 4
- Subtract 6/5 on both sides: 5x = 14/5
- Divide both sides by 5: x = 14/25
Step 5: Check to see if solution set (14/25, -2/5) is a solution.
- Substitute into an original equation: 10(14/25) - 16(-2/5) = 12
- Multiply each term: 28/5 + 32/5 = 12
- Add: 12 = 12
Here, we see that x = 14/25, y = -2/5 and solution (14/25, -2/5) indeed works.
Step 6: Find <em>x</em> <em>- y</em>
x = 14/25
y = -2/5
- Substitute: 14/25 - (-2/5)
- Simplify (change signs): 14/25 + 2/5
- Add: 24/25
Hope this helped! :)
