Answer:
24 Letters and 4 Postcards
Step-by-step explanation:
We have to set up a system of equations, since we have two unknown variables. Lets say postcards is the variable "x" and letters is the variable "y".
Our first equation will be the money spent: 0.33x + 0.49y = 13.08, this comes from knowing that it costs 0.33 dollars to mail a postcard and 0.49 dollars to send a letter.
The second equation is the total sent: x + y =28.
Now we need to solve for a single variable, let's do y (or letters). If we subtract y from both sides we get: x = 28 - y.
We can plug that into our first equatino to get: 0.33(28 - y) + 0.49y = 13.08.
If we multiply things out we get: 9.24 - 0.33y + 0.49y = 13.08, and now we have like terms. 9.24 + 0.16y = 13.08.
Subtract 9.24 from both sides to get: 0.16y = 3.84
Divide both sides by 0.16 to get: y = 24.
Now we can plug this into x + y = 28 to see that x= 4.
You could make sure this is correct by solving for x instead of y and do the same process.
Hope this helps.
<span>x=<span><span>16</span>+<span><span><span><span>16</span><span>√133</span></span><span> or </span></span>x</span></span></span>=<span><span>16</span>+<span><span><span>−1</span>6</span><span>√<span>133 ---- Use the quadratic formula. </span></span></span></span>
Answer:
3 cubic inches
Step-by-step explanation:
Using the formula, the volume of a cone
Subst. the known value of into the equation.
Thus, the volume of cone= 1(3)= 3 cubic inches.
Step-by-step explanation:
7.50= (1 + x/100 ) × 5.50
7.50/ 5.50 = 1+x/100
x/100 = 0.36
x= 36.36%
Answer:
porque hay un total de 21 canicas y 3 de ellas son rojas, en forma mas simple de cada 7 canicas una es roja o 1:7 es el razon de canicas rojas a todas
