Answer:
7 years
Step-by-step explanation:
Given that:
Let Richard's age = x
Elder sister's age = 2x
Youngwr sister's age = x - 2
Product of sisters ages = 70
2x * (x - 2) = 70
2x² - 4x = 70
2x² - 4x - 70 = 0
x² - 2x - 35 = 0
x² - 7x + 5x - 35 = 0
x(x - 7) +5(x - 7) = 0
(x - 7) or (x + 5) = 0
x = 7 or x = - 5
X can't be negative
Hence, x = 7
Richard is 7 years
Answer:
15
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>
Step-by-step explanation:
<u>Step 1: Define</u>
<em>Identify</em>
5a - 10b = 45
<em>b</em> = 3
<u>Step 2: Solve for </u><em><u>a</u></em>
- Substitute in <em>b</em> [Equation]: 5a - 10(3) = 45
- Multiply: 5a - 30 = 45
- [Addition Property of Equality] Add 30 on both sides: 5a = 75
- [Division Property of Equality] Divide 5 on both sides: a = 15
Answer:
No, a reasonable estimate is around 6 times $7 = $42
Step-by-step explanation:
$6.99 is rounded up to 7, and there are 6 people who ordered a $7 meal. And 6 times 7 is 42
Answer:
depands
Step-by-step explanation:
on how much ppl
