Cosine = adjacent / hypotenuse
cosine = 1 / square root (2)
Solve the following system using substitution:
{y + 2.3 = 0.45 x
{-2 y = -3.6
In the second equation, look to solve for y:
{y + 2.3 = 0.45 x
{-2 y = -3.6
-3.6 = -18/5:
-2 y = -18/5
Divide both sides by -2:
{y + 2.3 = 0.45 x
{y = 9/5
Substitute y = 9/5 into the first equation:
{4.1 = 0.45 x
{y = 9/5
In the first equation, look to solve for x:
{4.1 = 0.45 x
{y = 9/5
4.1 = 41/10 and 0.45 x = (9 x)/20:
41/10 = (9 x)/20
41/10 = (9 x)/20 is equivalent to (9 x)/20 = 41/10:
{(9 x)/20 = 41/10
{y = 9/5
Multiply both sides by 20/9:
Answer: {x = 82/9
{y = 9/5
Basically, you'd do:
0.2 * 52 (0.2 = 20%, 21% = 0.21)
Your Answer:
10.4
Answer:
<em>The number is 46</em>
Step-by-step explanation:
<u>Equations</u>
Suppose:
a = One digit of the number
b = Tens digit of the number
The sum of the digits is 10:
a + b = 10
The number expressed as two-digits quantity is ab, and its value is
10a+b
When we add 18 to that number, we have:
10a+b+18
And that is represented as the number reversed:
10a+b+18=10b+a
Simplifying:
9a+18=9b
Dividing by 9:
a + 2 = b
Substituting in the first equation:
a + a + 2 = 10
2a = 8
a = 4
b = a + 2 = 6
Thus the number is 46
17+8-9=17-1=16
Answer: C)16
