Answer:
49
Step-by-step explanation:
substitute b = - 6 and c = 7 into the expression and evaluate
c - 7b = 7 - (7 × - 6) = 7 - (- 42) = 7 + 42 = 49
Answer:
Dimensions of printed area
w = 8.95 cm
h = 13.44 cm
A(max) = 120.28 cm²
Step-by-step explanation:
Lets call " x " and "y" dimensions of the poster area ( wide and height respectively) . Then
A(t) = 180 cm² = x*y y = 180/ x
And the dimensions of printed area is
A(p) = ( x - 2 ) * ( y - 3 ) then as y = 180/x we make A function of x only so
A(x) = ( x - 2 ) * ( 180/x - 3 ) ⇒ A(x) = 180 - 3x - 360/x +6
A(x) = - 3x - 360 /x + 186
Taking derivatives on both sides of the equation we get:
A´(x) = -3 + 360/ x²
A´(x) = 0 -3 + 360/ x² = 0 -3x² + 360 = 0
x² = 120 ⇒ x = √120 x = 10.95 cm
And y = 180 / 10.95 ⇒ y = 16.44 cm
Then x and y are the dimensions of the poster then according to problem statement
w of printed area is x - 2 = 10.95 - 2 = 8.95 cm
and h of printed area is y - 3 = 16.44 - 3 = 13.44 cm
And the largest printed area is w * h = ( 8.95)*(13.44)
A(max) = 120.28 cm²
Answer:
1/5m - 20 = 1/5(m - 100)
Step-by-step explanation:
Answer:
5, 11
Step-by-step explanation:
the number is subtracting 4 adding 6 subtracting 4 adding 6
Answer:
C 8.9
Step-by-step explanation:
all these lines (from the same point of origin, cutting into and through a circle, ending at the far end of the circle they are cutting into) have the same relation of their lengths :
a×(a+b) is the same for all these lines.
with a being the first segment from the point of origin to touching the outside of the circle, and b being the length of the line inside the circle.
so,
4×(4+16) = 8×(8+2) = 80
this is correct for these two lines.
now, the line with the length x is a special case, as it does not really go through a circle, it only touches them.
but the length relation applies also to this line. it is just that the length inside the circle is 0.
so,
x×(x+0) = 80 (the same value as for the other lines)
must be true here too.
=>
x² = 80
x = sqrt(80) ≈ 8.9
