1: 19 (4x+25=6x -13, solve for x, 25+13=6x-13, 38=2x, x=19, 4(19)+25=101 6(19)-13+101)
2: 23 (3x-8=2x+15)
3: Madison has $59 and Saul has $31 (together they have $90 so divided by 2 and you get 45, Madison has 6 dollars more so subtract 6 from Saul and ad 6 to Madison, make sure that when you ad them you get $90)
4 : 5 weeks ($3 each week, so you multiply 3x5 and get 15. 15+57=72 but the problem says more then so maybe it’s 6 weeks cause that’s $75)
5: 10 weeks (he has 1,800 and needs 2,150, subtract 1,800 from 2,150 for how much he needs. You get 350. He needs that and he makes 35 a week so that would be 350 divided by 35, which is 10)
6:20 miles (it’s 2.25 for that’s first mile. He spent 6.05 so subtract 2.25 from 6.05 and you get 3.80, 3.80 divided by 0.20 is 19, then you need to add that first mile and it’s 20)
7: 6 figures in a complete set (Charlie starts out with 2 and Patrick starts out with 20 individual figures. Charlie has 6 sets and Patrick has 3, i multiplied the number of sets they had by 6 then added their individual figures until they numbers matched up)
8: an orange has 45 calories and an apple has 75 calories (5x-150=3x, 5x-3x= -2x, -2x divided by -150 = 75, 75-30 is 45. 75 is the apple and because it’s 30 more you subtract 30 for orange)
<span>I can solve for x and y
A) 2x - 4y = 12
A) 2x = 4y + 12
A) x = 2y + 6
Substituting into B
B) 3* (2y +6) - 5y = 20
B) 6y + 18 -5y = 20
B) y = 2
B) x = 10
</span>
Hello,
Use the factoration
a^2 - b^2 = (a - b)(a + b)
Then,
x^2 - 81 = x^2 - 9^2
x^2 - 9^2 = ( x - 9).(x + 9)
Then,
Lim (x^2- 81) /(x+9)
= Lim (x -9)(x+9)/(x+9)
Simplity x + 9
Lim (x -9)
Now replace x = -9
Lim ( -9 -9)
Lim -18 = -18
_______________
The second method without using factorization would be to calculate the limit by the hospital rule.
Lim f(x)/g(x) = lim f(x)'/g(x)'
Where,
f(x)' and g(x)' are the derivates.
Let f(x) = x^2 -81
f(x)' = 2x + 0
f(x)' = 2x
Let g(x) = x +9
g(x)' = 1 + 0
g(x)' = 1
Then the Lim stay:
Lim (x^2 -81)/(x+9) = Lim 2x /1
Now replace x = -9
Lim 2×-9 = Lim -18
= -18
Answer:
I think ITS B
Step-by-step explanation:
Hope this helped
-BB
