Answer:
B 9, -9
Step-by-step explanation:
x^2 - 81 = 0
Add 81 to each side
x^2 = 81
Take the square root of each side
sqrt(x^2) = sqrt(81)
x = ±9
Let's say Jackson's age now is x.
In 20 years, (so 20+x), Jackson seven years ago will be 2/5ths of that age.
So 2/5(20+x)=x-7
Then you solve the equation
8+2/5x=x-7
15=3/5x
x=25
Jackson is 25 years old.
Let's check our answer! In 20 years, Jackson will be 45. 7 years ago, he was 18. 2/5 of 45 is 18. Our answer is correct!
- 38.79
- 3053.63
- 904.78
- 2544.69
- 226.19
- 402.12
- 1072.33
- 1526.81
- 28.73
- 113.1
- 3801.33
- 268.08
- 2094.4
- 75.4
- 94.25
- 37.7
- 1884.96
- 2065.24
- 19861.7
- 1385.44
- 287.98
- 4.19
- 3619.11
- 113.1
- 50.27
I did this really quick so I hope all the answers are right, and double check them if you have time just in case
The area of the rectangular roof shingle is 70 inches
Answer:
glasses of milk=4
quatar pounds servings of meat =5
two slices of whole grains bread =8
Step-by-step explanation:
Let m= milk
r=meat
b=bread
0.1m+3.4r+2.2b=35 (1)
8.5m+22r+10b=224 (2)
m+20r+12b=200 (3)
Multiply (1) by 85 and (2) by 1
8.5m+289r+187b=2,975 (4)
8.5m+22r+10b=224 (5)
Subtract (5) from (4)
267r+177b=2,751 (6)
Recall,
8.5m+22r+10b=224 (2)
m+20r+12b=200 (3)
Multiply (2) by 1 and (3) by 8.5
8.5m+22r+10b=224 (7)
8.5m+170r+102b=1700 (8)
Subtract (7) from (8)
148r+92b=1,476 (9)
Recall,
267r+177b=2,751 (6) and
148r+92b=1,476 (9)
Multiply (6) by 148 and (9) by 267
26196b=407,148 (10)
24564b=394,092 (11)
Subtract (11) from (10)
1,632b=13,056
Divide both sides by 1,632
b=13,056/1,632
b=8
Substitute the value of b in (9)
148r+92b=1,476 (9)
148r+92(8)=1,476
148r+736=1,476
148r=1,476-736
148r=740
Divide both sides by 148
r=740/148
r= 5
Substitute the value of b and r in (1)
0.1m+3.4r+2.2b=35 (1)
0.1m+3.4(5)+2.2(8)=35
0.1m+17+17.6=35
0.1m+34.6=35
0.1m=35-34.6
0.1m=0.4
Divide both sides by 0.1
m=0.4/0.1
m=4
4 glasses of milk, 5 quatar pounds servings of meat and 8 two slices of whole grains bread will supply the required nutrients.
