So x + y = 45, and 4x + 5y = 195. Get y by itself. Subtract x from both sides in the first equation to get y = 45 -x, and subtract 4x from the second equation to get 5y = 195 - 4x. Divide by 5 to both sides to get y = 39 - 4/5x. 39 - 4/5x = 45 - x. Add x to both sides to get 39 - 1/5x = 45. Subtract 39 from both sides to get -1/5x = 6. Divide by -1/5 to get x = -30, or 30. In the first equation, do 30 + y = 45. Subtract 30 from both sides to get y = 15. Check. 4(30) + 15(5) = 195, or 120 + 75 = 195.
Si, los dos son iguales
Cuando haces 5x=15, la división dice que x = 3. Para 2x=6 puedes usar el resultado de x=3 de la problema de antes, y cuando te usas esto va a ver que 2 de x cuando x=3 es igual a 6, y por eso 5x=15 y 2x=6 son equivalentes.
We are asked to find the principal value of
cos ⁻¹ (0.69)
which is just the least positive angle
cos ⁻¹ (0.69) = 46.37°
Other values of
cos ⁻¹ (0.69) is
46.37° - 180° n
where n is a whole number
Answer:
<h2>
the answer is</h2><h2>
166 cm²</h2>
Step-by-step explanation:
we know that
surface area of the prism=2*area of the base+perimeter of the base*height
step 1
find the area of the base
area of the base=length* width
length=5 cm
width=4 cm
area of the base=5*4-----> 20 cm²
step 2
find the perimeter of the base
perimeter=2*[length+width]-----> 2*[5+4]----> 18 cm
step 3
height=7 cm
step 4
find the surface area
surface area of the prism=2*area of the base+perimeter of the base*height
surface area of the prism=2*20+18*7----> 166 cm²
