Answer:
5 marbles are black.
Step-by-step explanation:
7-2=5
7 is the value of x, and 64° is the measure of the unknown angle.
Triangle angles of 76°, (9x+1)°, and 40° are provided.
According to the triangle's "angle sum property," a triangle's angles add up to 180 degrees. Three sides and three angles, one at each vertex, make up a triangle. The sum of the interior angles in a triangle is always 180o, regardless of whether it is acute, obtuse, or right.
One of the most commonly applied properties in geometry is the triangle's angle sum property. Most often, the unknown angles are calculated using this attribute.
Now, the total of a triangle's three angles equals
76°+(9x+1)°+40°= 180°
⇒ 116+9x+1 = 180
⇒ 9x + 117 = 180
⇒ 9x = 63
⇒ x = 7
So, 9x+1=64°
As a result, x is equal to 7 and the unmeasured angle is 64°.
To learn more about the angle sum property of a triangle, refer to this link:
brainly.com/question/8492819
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Answer:
B) 5
Circle is 360 degr. So (21x+9) +(23x-5) +(26x+6)=360
Combine like terms 70x+10=360
Additive inverse -10 from both sides, 70x= 350
Divide both side by 70 division Property of Equality x=5.
Check your answer by substituting 5 back into original solution!
Step-by-step explanation:
So first create and define your variables:
Z = amount of zebra fish
N = amount of neon tetras
Now create your equations:
2z+2.15n=31.20
z+n=15
This is your system. There are multiple methods to use but in this problem I’ll use the substitution method by simplifying the bottom equation.
2z+2.15n=31.20
z=15-n
Now I’ll plug the bottom equation into the top one.
2(15-n)+2.15n=31.20
And just solve from here.
30-2n+2.15n=31.20
0.15n=1.20
n=8
So he bout 8 neon tetras, and 15-8= 7, so he bought 7 zebra fish