Answer:
it would be 4
12-4×2=12-8=4
Step-by-step explanation:
hope it helps you
Answer:
x = (1 + sqrt(253))/14 or x = (1 - sqrt(253))/14
Step-by-step explanation:
Solve for x:
7 x^2 = x + 9
Subtract x + 9 from both sides:
7 x^2 - x - 9 = 0
x = (1 ± sqrt((-1)^2 - 4×7 (-9)))/(2×7) = (1 ± sqrt(1 + 252))/14 = (1 ± sqrt(253))/14:
Answer: x = (1 + sqrt(253))/14 or x = (1 - sqrt(253))/14
Let us bear in mind the equivalent value of these coins:
One dime = $0.10
One quarter = $0.25
Let x = number of dimes
y<span> = number of quarters</span>
Since the boy has 70 coins in total, we can say that:
<span>x + y = </span><span>70 </span>(can be written as x = 70 – y)
Since the boy has a total of $12.40, we can say that:
0.10x + 0.25y = 12.40
To solve this problem, we need to solve this system of equation. We have to substitute the value of x as written in the first equation (x = 70 –y)
0.10(70 – y) + 0.25y = 12.40
7 – 0.10y + 0.25y = 12.40
0.15y = 5.40
y = 36
X = 70 – 36
X = 34
Therefore,<span> the boys </span>has<span> 34 dimes and 36 quarters. To check our answer, we just have to check if his money would total $12.40.</span>
34 dimes = $3.40
36 dimes = $9.00
<span>Total </span><span>$12.40</span>
Year 1: 500 + 0.25*500 = 500 [1 + 0.25]
Year 2: 500*[ 1 + 0.25] * [1 + 0.25] = 500 [1 + 0.25]^2
Year x: 500 [1 + 0.25]^x
Option d: A(x) = 500[1 + .25]^x, where .25 is the interest rate
