It is given that batteries come in a packs of 4. It means in each pack there are 4 batteries.
Joe used 58 batteries . So to find the total number of packets of batteries joe has to open is
Number of batteries used / Total number of batteries in each packet
= 58 / 4
= 14.5
The number of battery can not be in decimal. So we will round the answer to integer. If we round it to 14 it means 14 packets. But in 14 packets there are 14*4 = 56 batteries .
But we know that Joe used 58 batteries. So we will round the final answer to 15.
It means Joe has to open 15 packets of batteries.
If you need an equation it is -3.4x=21.5
You simply divide both sides by -3.4 to get x=-6.32
if that's not right then just get on a calculator and calculate by doing what I said to divide
It should be 3.75 think of it as a dollar 3/4 of a dollar is .75
Answer:
1 Multiply the first equation by -1 then add the equations together
3. Multiply the second equation by -1 then add the equations together
4. Multiply the first equation by -2 then add the equations together
5. Multiply the first equation by 2 the second by -1 then add the equations together
Step-by-step explanation:
x+y = 7
2x+y = 5
1 Multiply the first equation by -1 then add the equations together
-x+-y = -7
2x+y = 5
---------------
x =-2 then solve for y
2. Multiply the second equation by -1 first equation by -1 then add the equations together
-x+-y = -7
-2x-y = -5
---------------
-3x -2y = -12
Still have both variables
3. Multiply the second equation by -1 then add the equations together
x+y = 7
-2x-y =- 5
----------------------
-x = 2
4. Multiply the first equation by -2 then add the equations together
-2x+-2y = -14
2x+y = 5
--------------
-y = -9
5. Multiply the first equation by 2 the second by -1 then add the equations together
2x+2y = 14
-2x-y = -5
--------------
y = 9
