He is incorrect because he multiplied the bases.
The answers are: D and C and A and E
because:
B 3(x - 5) - 2(6x2 + 9x + 5)=<span><span><span>−<span>12<span>x^2</span></span></span>−<span>15x</span></span>−<span>25
</span></span>F (4x2 - 13x - 7) - (16x2 + 9x - 5)=<span><span>−<span>12<span>x2</span></span></span>−<span>22x</span></span>−<span>2
E </span>(-15x2 + 9x - 10) + (3x2 - 10x - 5)=<span><span>−<span>12<span>x^2</span></span></span>−x</span>−<span>15</span>
Answer:
3 triangles
Step-by-step explanation:
Perimeter of triangle = a + b + c
Given that :
P = 12
and a, b, c are natural numbers
Let :
Side A = a
Side B = b
Side C = 12 - (a + b)
Side A + side B > side C - - - (condition 1)
a + b > 12 - (a + b)
a + b > 12 - a - b
a + a + b + b > 12
2a + 2b > 12
2(a + b) > 12
a + b > 6
Side A - side B < side C
a - b < 12 - (a + b)
a - b + a + b < 12
2a < 12
a < 6
b < 6 (arbitrary point)
Going by the Constraint above :
The only three possibilities are :
(2, 5, 5)
(3, 4, 5)
(4, 4, 4)
Total number of triangle = 3
Equilateral triangle (all 3 sides equal) = (4, 4, 4) = 1
Isosceles triangle (only 2 sides equal) = (2, 5, 5) = 1
The value of the expression will be equal to 145.
<h3>What is an expression?</h3>
The mathematical expression combines numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.
Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.
Given that make an expression for divide 50 by half and add 20 and multiply by 2.
The expression will be solved as below,
E = 50/2 + 25 x 2 + 50 + 20
Solve the above expression by PEMDAS,
E = 25 + 50 + 70
E = 145
To know more about an expression follow
brainly.com/question/25968875
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Answer:

Step-by-step explanation:
<u>Distribute the 9:</u>
<u />
<u>Subtract x on both sides:</u>
<u />
<u>Subtract 9 on both sides:</u>
<u />
<u>Divide both sides by 8:</u>
