2x+y=9
3x+5y=19
I will do this problem in 2 ways. I.)Substitution II.)Elimination
Solution I.) Substitution
We can subtract 2x from both sides in the first equation.
y=9-2x
Now we can substitute the y in the second equation with 9-2x
3x+5(9-2x)=19
-7x+45=19
-7x=-26
x=26/7
y=9-2(26/7)=11/7
Solution II.)Elimination
We can multiply both side of first equation by 5 to get a 5y in both equations.
10x+5y=45
Now because both are positive 5y we just need to do simple subtraction of the 2 equation, each side respectively.
(10x+5y)-(3x+5y)=45-19
7x=26
x=26/7
2*26/7+y=9
y=11/7
Ultimately you get the same answer, both are viable methods, some problems are faster with one method but I recommend mastering both since they are very useful.
<h2><u>Solu</u><u>tion</u><u>:</u></h2>
360° ÷ 10 ÷ 2 = 18°
So the length of the decagon side is:
10 × tan18° × 2 = 20 × tan18°
The area is: ½ × 20 × tan18° × 10 × 10 = 1000 × tan18°
≈ 324.9
.: <u>3</u><u>2</u><u>4</u><u>.</u><u>9</u> is the final answer.
<em>I</em><em> </em><em>h</em><em>ope</em><em> </em><em>this</em><em> helps</em><em>. </em>
Answer:
B
Step-by-step explanation:
Answer:
Mark brainliest please if i am correct one more brainliest please
Step-by-step explanation:
A=a+b
2h=15+25
2·5=100
6 and 1/3 or 19/3 or if you need the decimal 6.3 repeating