12 - 2x = -2(y - x)
12 - 2x = -2y - (-2x)
12 - 2x = -2y + 2x
12 - 2x - 2x = -2y + 2x - 2x
12 - 4x = -2y
12 - 12 - 4x = -2y - 12
-4x = -2y - 12
-4x/4 = -2y/4 - 12/4
-x = -0.5y - 3
-x/-1 = -0.5y/-1 - 3/-1
x = 0.5y + 3
or
x = 3 + 0.5y
Answer:
1) 6 balls
Step-by-step explanation:
x = number of balls Elsa can shoot
x + 6 = number of balls Anna can shoot
18 = number of balls together they can shoot
x + (x + 6) = 18
x + x + 6 = 18
2x + 6 = 18
2x = 18 - 6
2x = 12
x = 6
2)2) 20x (3÷ 4)=90 120-90=30 thus left seat has 30 seating capacity.
3)Let x & y be packets of [a] type & [b] type detergent sold
Then 9x +7y =180
Let us say x=7
Then 9*7+7y =180
7y =180–63 = 117
y =117/7=19.2 this will not do as it contains decimal not whole number
Say x=6
Then 9*6 +7y =180
7y=180–54 =126
y =126/7 =18 this is acceptable as it is whole number
Answer: 6 packets of (a) and 18 packets of type (b) were sold to get 180Php
4) 5,6,7 female piglets
5)1kg. of rice is Php. 90.00 . Mang Tommy pays Php.360.00 for 4kg. of rice.
4kg of rice - Php. 360.00
3kg of pork- Php. 390.00
1kg of rice is Php. 90.00
1kg of pork is Php. 130.00
Answer:
8 boards.
Step-by-step explanation:
Since he bought a few of each length. The only combination that works is when he bought 5 of the 4 ft long board so 4×5=20. Than he bought 3 of the 5ft boards 3×5=15. 20+15=35 ft worth of boards.
Answer:
It will take 7 years ( approx )
Step-by-step explanation:
Given equation that shows the amount of the substance after t years,
Where,
= Initial amount of the substance,
If the half life of the substance is 19 years,
Then if t = 19, amount of the substance = 
,
i.e.
Taking ln both sides,
Now, if the substance to decay to 78% of its original amount,
Then 
Again taking ln both sides,
Hence, approximately the substance would be 78% of its initial value after 7 years.
316-226=90 90 is your answer
