If a triangle has sides of 7 cm and it is an equilateral you can draw a line right down the middle to form two congruent triangles.
These smaller triangles have a hypotenuse of 7cm and a base of 3.5 cm (7/2)
To work out the height, use Pythagoras’ theorem.
a^2 + b^2 = c^2 where c is the hypotenuse and a and b are the other two sides
7^2 - 3.5^2 = 36.75
Square root answer
= 6.06 cm
That’s the height of the triangle
Area of a triangle is base x height divided by 2
So 7 x 6.06 = 42.43…
/2
= 21.2 cm^2 to one d.p
Hope this helped!
Please mark Brainliest!!
I think the best answer would probably be 1
Let the number of apples be x and that of pears be y, then:
0.64x + 0.45y = 5.26 . . . (1)
0.32x + 0.39y = 3.62 . . . (2)
(2) x 2 => 0.64x + 0.78y = 7.24 . . . (3)
(1) - (3) => -0.33y = -1.98
y = -1.98 / -0.33 = 6
From (2), 0.32x + 0.39(6) = 3.62
0.32x = 3.62 - 2.34 = 1.28
x = 1.28 / 0.32 = 4
Therefore, he bought 4 apples and 6 pears.
Answer:
2.) 8/5
Step-by-step explanation:
a4 = 8/5
9514 1404 393
Answer:
a) 600
b) see below
c) 1.26 hours
Step-by-step explanation:
a) The value of y when x=0 is the coefficient of the exponential term:
y = 600·3^(-0) = 600·1 = 600
There were 600 atoms to start.
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b) see attached for a graph
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c) The graph shows 150 atoms at t = 1.26, about 1.26 hours after the start of time counting.
If you want to find that value algebraically, substitute for y and solve for x. Logarithms are involved.
150 = 600·3^(-x)
150/600 = 3^(-x)
log(1/4) = -x·log(3)
x = -log(1/4)/log(3) = log(4)/log(3) ≈ 1.2618595
After about 1.26 hours, there were 150 atoms.