① 5x-20% x = 19.5 ② 2 (x-4) = 3 (X-12) ③3x-0.8×75%=2.1
5x-20%x=19.5
4.8x=19.5
x=19.5÷4.8
x=4.0625
2(x-4)=3(x-12)
2x-8=3x-36
3x-2x=36-8
x=28
3x-0.8×75%=2.1
3x-0.6=2.1
3x=2.1+0.6
3x=2.7
x=2.7÷3
x=0.9
RELATED INFORMATIONS
- 1. Using Chen FA's formula: (1) (x-2y) 178; (x + 2Y) 178; (2)(a-2b+3)(a+2b-3)
- 2. Solution equation: 3x + 3 (2x-3) = 12 - (x + 4)
- 3. Factorization factor X ^ 2-2xy + y ^ 2 + 2x-2y-8
- 4. The function image is used to solve x, and the written calculation test is: (1) 5x-3 = x + 2; (2) 0.5x-4 = 3x + 2
- 5. A two digit number, exchange its ten digit number and one digit number, and the two digit number obtained is four times seven times of the original number. How many such two digits are there? speed
- 6. 5x-18=3-2x fast
- 7. What's the difference between arithmetic shift left / right and logic shift left / right in Verilog
- 8. General solution of differential equation XDY / DX + y = Xe ^ x
- 9. General solution of differential equation (x ^ 2 cosx-y) DX + XDY = 0
- 10. Given that Ω = {(x, y) | x | ≤ 1, | y | ≤ 1}, a is a region bounded by the curve y = x & # 178; and y = x & # 189; if a point P is randomly cast on the region Ω Find the probability of P point falling into area A
- 11. Solve this inequality: 1 / 2x-1 ≥ 7-3 / 2x How to solve this inequality? Please write out the process
- 12. Calculate 1 / X (x + 1) + 1 / (x + 2) (x + 1). + 1 / (x + 2008) (x + 2009) and find the value of the algebraic expression when x = 1
- 13. When the line X-my + 3 = 0 and the circle x ^ 2 + y ^ 2-6x + 5 = 0 intersect, tangent and depart from the circle respectively, the range of M is calculated The process
- 14. If the vector OA, ob, OC, OD satisfies: OA = xob + yoc + Zod (x, y, Z belong to R) and X + y + Z = 1, then a, B, C, D are coplanar
- 15. If the two sides of a triangle are 5 cm and 8 cm in length, how many cm is the third side?
- 16. In rectangular trapezoid ABCD, ad is parallel to BC, AB is vertical to BC, and the angle DCB is 75 degrees. The other vertex e of equilateral triangle with CD as one side is on the waist ab Find AB = BC If f is a point on the line CD, the angle FBC = 30 ° and DF = FC are proved
- 17. If it is known that the length of the side edge of the regular triangular prism abc-a1b2c3 is equal to the length of the side edge of the bottom, what is the sine value of the angle between Ab1 and acc1a1
- 18. It is known that P1 (2,3), P2 (- 1,4), P is on the extension line of the straight line p1p2, and the vector | p1p | = 2 | PP2 |
- 19. As shown in the figure, in the trapezoidal ABCD, ad ∥ BC, AC and BD intersect at O, and parallel lines passing through o intersect AB and CD at e and f respectively. (1) prove that OE = of; (2) if ad = 3, BC = 4, find the length of EF
- 20. In diamond ABCD, the point P and Q are on the edge AB and BC respectively, and AP = BQ. Try to judge the shape of △ PDQ and prove it